Copyright: © Softcover International Ltd 1999.


Contents

The following Help Topics are available:

Tutorial

Tutorial

General

What is Scan2CAD?

Preparing a raster file for conversion

How to use Scan2CAD

The Scan2CAD interface

Icons

Short-cut keys

Possible Problems

Possible problems with reading a raster image into Scan2CAD

Possible conversion problems

Possible problems with editing vectors

Error messages about temp files, creating files, writing files or allocating image memory

Menus

File Menu

View Menu

Edit Raster Menu

Edit Vector Menu

Type Menu

OCR Menu

Run Menu

Batch Menu

For Help on Help, Press F1


What is Scan2CAD?

Scan2CAD is a raster to vector converter – a software program that automatically converts raster files into DXF vector files that can be read into a CAD program. This saves considerable time in the conversion of paper-based drawings into drawings that you can add to, edit, and print from your CAD system.

Raster files

A raster file is the type of file that is created when you scan a paper-based drawing into an electronic format that your computer can read. There are various types of raster file. Scan2CAD can read IMG, PCX, BMP and TIFF raster files.

A raster file is made up of little squares called pixels as shown in the diagram below. Lines and arcs are represented by filling in the appropriate pixels.

Some types of raster file take up more space on your hard disk than other types. For example, BMP files take up more space than TIFF group 4 files. You can use Scan2CAD’s Save Raster As function to convert one type of raster file to another so you can maximise hard disk space.

Vector files

A vector file is a file where lines and arcs are stored as vectors, i.e. as precisely defined entities drawn between coordinates and with properties such as radii (in the case of arcs and circles), rather than as lumpy groups of pixels.

Scan2CAD converts raster files to a type of vector file called a DXF file. DXF (Data eXchange Format) is a type of vector file designed for exchanging drawings between different CAD programs. DXF files can be read by all CAD packages.

Why convert raster files to vector files?

You will probably be able to load a raster file into your CAD program - most CAD programs can import and display raster files. However, once you have imported a raster file into your CAD program you will find that all you can do is look at it or trace over it. You will not be able to make any changes to it.

This is because CAD programs can only work with vector files. If you want to edit a raster file in your CAD program you must first convert it to a vector file. You do this using raster to vector conversion software like Scan2CAD.

Once you have converted the raster file to vector you will be able to import it into your CAD program and edit it just like any other drawing you have created using your CAD program.


How to use Scan2CAD

To use Scan2CAD, you need to follow these steps:

1.	Create the raster file

The raster file you create must be good quality and must be in a format that Scan2CAD can read. See Preparing a raster file for conversion.

2.	Read the raster file into Scan2CAD

Once you have created a suitable raster file, open it in Scan2CAD using Open Raster File in the File Menu. If you have problems reading a raster file into Scan2CAD, see Possible problems with reading a raster image into Scan2CAD.

3.	Clean up the raster file (optional)

If the quality of the raster image is poor you can “clean” it using the tools in Scan2CAD’s Edit Raster Menu. For example, you can draw over individual badly-scanned raster lines or arcs using Raster Draw Mode. Use Speckle Removal to remove black speckles from white areas. Use Hole Removal or Thicken Image to fill white holes in black areas. If the lines are very thin, thicken them using Thicken Image.

4.	Select OCR and vectorisation settings

OCR Settings in the OCR Menu determines how raster text will be converted if you choose to recognise text on your drawing using OCR.

Vectorisation settings are the values of eight variables that control the conversion of lines and arcs from raster to vector. For successful conversion, different drawings and applications need different vectorisation settings. For example, architectural floorplans tend to be made up of horizontal and vertical lines and Scan2CAD needs to try to keep these lines exactly horizontal and vertical. Maps on the other hand are made up of lines that go in all directions and Scan2CAD must not try to make these lines exactly horizontal and vertical.

Vectorisation settings are set in the Type Menu. Before you convert an image, go to the Type Menu and choose the option that best describes the drawing you want to convert: Architectural, Electrical, Mechanical, CNC Profiles, Map, Sketch, Outline or Scanline. Use Outline or Scanline to convert solid black areas like logos. Outline outlines solid areas, while Scanline converts them to a series of horizontal parallel lines.

The default vectorisation settings in the Type Menu will normally give good results without modification, but you can edit them to optimise the conversion of a drawing, part of a drawing or a group of drawings. You can save your own settings for future re-use.

5.	Convert the raster file to a vector file

Scan2CAD will either convert the whole raster file or part of a raster file. It will convert whatever is currently displayed on the screen. Because it only converts what is on the screen, you can convert different parts of the raster image using different OCR and/or vectorisation settings.

There are three conversion options:

OCR - performs OCR on text in the raster image.

Vectorisation - converts the raster image to vectors, excluding text on which OCR has already been performed.

All - performs OCR on the text and converts the raster image to vectors.

For best results when converting a drawing that contains text you should use OCR to convert the text on the drawing first. Once you have achieved the best possible OCR conversion, use Vectorisation to vectorise the rest of the drawing.

You can Undo the last conversion you performed by selecting UnDo OCR and/or UnDo Vectorisation from the Run Menu.

If OCR, Vectorisation or All recognise text or vectors poorly, see:

Possible problems with OCR conversions.

Possible problems with drawing conversions.

6.	Tidy up the vector file (optional)

You can use the tools in the Edit Vector Menu to delete unwanted vectors from the vector file and to draw new vectors. There are also tools for moving vector end points, joining and splitting vectors, converting lines to arcs and converting arcs to lines.

You may prefer to tidy the vector file in your CAD program where you will have additional tools for trimming etc.

7.	Save the vector file

Save the DXF file using Save As DXF in the File Menu.

8.	Import the vector file into your CAD program

Once you have saved the vector file as a DXF file, you can import it into your CAD program. See the documentation that came with your CAD program for details on how to import a DXF file.

Scan2CAD will not create a perfect vector file, but it is usually much quicker to use your CAD program to tidy up a drawing that Scan2CAD has vectorised to redraw it from scratch.


Scan2CAD interface

The Scan2CAD screen is divided into the parts shown below.

Title Bar

Once you have used Open Raster File in the File Menu to load the raster file you want to convert, the name of the raster file - Mech.Tif in the diagram above - is displayed in the Title Bar. When you convert the raster file to vectors, the message in the title bar changes to Mech.Tif >> Untitled.Dxf. When you use Save As DXF in the File Menu to save the vectorised file, the name of the vector file is also shown in the Title Bar - Mech.Dxf in the diagram above.

The buttons on the Title Bar are standard Windows buttons that will be different depending on the version of Windows you are using. You can use these to switch between the programs currently running on your PC (e.g. Scan2CAD and your CAD program) and to minimise or maximise Scan2CAD. If you don't know how to use these buttons, see the documentation that came with your copy of Windows.

Menu Bar

Most Scan2CAD functions can be selected from the pull-down menus in the Menu Bar. The type of command in each menu is summarised below:

•	File: opening and saving raster and vector files; exiting Scan2CAD.

•	View: controlling what you see on the screen; zooming in.

•	Edit Raster: tidying up the raster file. Includes commands for drawing onto the raster image, erasing areas of the raster image, despeckle and deskew.

•	Edit Vector: tidying up the vector file. Includes commands for drawing, erasing and editing vectors.

•	Type: selecting the optimum settings for vectorising lines and arcs depending on the type of drawing being converted (architectural, mechanical etc.)

•	OCR: selecting the optimum settings for OCR of text.

•	Run: vectorising and performing OCR on the raster image.

•	Batch: converting multiple raster files.

•	Help: Help on Scan2CAD.

Toolbar

The Toolbar contains icons that provide short-cuts to some of the functions in the pull-down menus. See Icons.

Work Area

The functions in the View Menu control what is displayed in the work area, including:

•	Which image is displayed - raster, vector or both.

•	Zooming in and out.

•	The colours that vectors are displayed in.

•	Display of grab points.

•	Cursor type.

Scroll Bars

You can pan around the image on the screen using the scroll bars. See also Panning.

Fill Box

Double clicking on the Fill Box accesses Fill command.

Where a zoomed view only takes up part of the screen, Fill increases the amount of the image that is displayed to fill the screen. Subsequent uses of Fill shrink what is displayed slightly so you can see more of the image on the screen.

Information Bar

The Scan2CAD Information Bar comprises four parts: the Message Area, the Percentage Bar, the Coordinate Display and the Status Display.

The Message Area on the left of the Information Bar has three functions.

•	It prompts you to do things. Prompts are written in black on a yellow background.

•	When you pass your cursor over an icon in the Toolbar, it tells you what that icon does. Icon explanations are written in black on a grey background.

•	It tells you what Scan2CAD is doing. For example, during a conversion it tells you which phase of the conversion Scan2CAD is on. Messages of this type are also written in black on a grey background.

The Percentage Bar gives you an indication of how each phase of the current conversion is progressing and how far it has to go before completion. The Percentage Bar also indicates when the system is working, for example when it is loading a raster image.

The Coordinate Display shows the coordinates of the top left corner of the current view and the bottom right corner of the current view. Coordinates are measured in pixels.

The Status Display on the right of the Information Bar shows whether Attach Grab Points is on or off. If Attach Grab Points is on, the Status Display reads ATON. If Attach Grab Points is off, the Status Display reads ATOFF.


File Menu

The File Menu contains functions for opening and saving raster and vector files.

Open Raster File

Save Raster

Save Raster As

Save Raster Part As

Close Raster

Auto Save Raster

Raster TIFF Warnings

Open Vector File

Merge Vector

Save DXF

Save As DXF

Close Vector

Auto Save Vector

Scale Vectors

Save Text File

Exit


Open Raster File (File Menu)

•	NOTE: You should never attempt to convert a raster file from a floppy disk. Always copy the file to your hard drive using File Manager or Windows Explorer before you try to open it in Scan2CAD.

Open Raster File opens the raster file that you want to convert to DXF.

When you select Open Raster File, a standard Windows Open dialogue box appears. Select the raster file you want to convert and click on OK.

The raster file is displayed on the screen and its name appears in Scan2CAD's Title Bar at the top of the screen.

If you have problems reading a raster file into Scan2CAD, see Possible problems with reading a raster image into Scan2CAD.

•	NOTE: If you are using Windows ‘95 or ‘98 and you try to open an image that is larger than 32,000 pixels in either width or height the message Raster image extent limits exceeded will appear. This is because of a Windows-imposed limit on raster image size in Windows ‘95 and ‘98. In Windows NT there is effectively no limit on raster image size.

The Raster image extent limits exceeded message tells you how many “tiles” Scan2CAD will have to split the image up into in order to process it. For example, it may have to split the image into 4 columns by 2 rows (8 tiles). You need to open and convert each of these tiles separately, and then join them back together again after conversion.

If you click on Yes to the Raster image extent limits exceeded message, a dialogue box asking for the column and row number of the tile you want to convert will appear. So for example if Scan2CAD has split the image into 4 columns by 2 rows, enter column and row numbers of 1 and 1 first of all. Convert tile 1,1 and save it using Save As DXF in the File Menu. Then use Open Raster File to load tile 1,2 and convert it and save it. Repeat for each tile until the whole image has been converted.

When all the tiles have been converted, join them back into one file using Merge Vector in Scan2CAD. Alternatively, join them back together in your CAD program.


Save Raster (File Menu)

Save Raster saves the raster file under its existing name.


Save Raster As (File Menu)

Save Raster As saves the raster file under a new name. You can save the raster file in any of the following raster file formats, regardless of the original format of the file:

•	IMG

•	PCX

•	BMP (uncompressed)

•	TIFF (uncompressed, packbits, CCITT fax group 3 or CCITT fax group 4 compressed formats).

This means you can convert raster files from one raster format to another. For example, if you load a BMP file into Scan2CAD you can save it as a TIFF Group 4 compressed file which will take up much less hard disk space.

When you select Save Raster As, a standard Windows Save dialogue box appears. Use the Save File as Type part of the dialogue box to select the raster format you want to save the file as. Then type a name for the file into the File Name part of the dialogue box and click on OK.


Save Raster Part As (File Menu)

Save Raster Part As saves part of the raster file under a new name.

Before you use Save Raster Part As, choose the part of the raster image you want to save by zooming into it or by selecting it using Window Mode.

When you select Save Raster Part As, a standard Windows Save dialogue box appears. Use the Save File as Type part of the dialogue box to select the raster format you want to save the file part as (IMG, PCX, BMP or TIFF). Then type a name for the file part into the File Name part of the dialogue box and click on OK.


Close Raster (File Menu)

Close Raster closes the raster file. It does not close the vector file if there is one open and it does not exit Scan2CAD.


Auto Save Raster (File Menu)

If Auto Save Raster is set to 10, 20 or 30 Scan2CAD automatically saves the raster image every 10, 20 or 30 minutes. If Auto Save Raster is set to 0, Scan2CAD does not automatically save the raster image.

Auto Save Raster saves the image under the file names Autobak1.??? and Autobak2.??? on a rotating basis, where ??? represents the current file type being edited (PCX, IMG, BMP or TIF).

Because raster files can be very large you should only use Auto Save Raster if you are doing a lot of raster file editing. If you do use Auto Save Raster, you should delete Autobak1 and Autobak2 after each Scan2CAD session to conserve disk space.


Raster TIFF Warnings (File Menu)

TIFF is a varied and constantly changing file format. If you import a TIFF file into Scan2CAD that uses a later TIFF format than the one Scan2CAD reads, or that uses a non-standard TIFF format, Scan2CAD will generate TIFF File Error or TIFF File Warning messages.

Unless the TIFF file's format is significantly different to the format that Scan2CAD reads, these messages are unlikely to affect Scan2CAD's ability to read in and convert the TIFF file. They are for information only.

If the Raster TIFF Warnings option is ticked, Scan2CAD will display any TIFF File Error or TIFF File Warning messages it generates. Simply click on OK to dismiss these messages if and when they appear. If the Raster TIFF Warnings option is not ticked, Scan2CAD will not display any messages.


Open Vector File (File Menu)

Open Vector File opens a DXF vector file.

When you select it, a standard Windows Load dialogue box appears. Select the DXF file you want to load, then click on OK. The vector file is displayed on the screen and its name appears in Scan2CAD's Title Bar.


Merge Vector (File Menu)

Merge Vector merges different DXF files to create a single DXF file.

Before using Merge Vector, use Open Vector File in the File Menu to load one of the DXF files to be merged. Merge Vector will merge the other DXF files into this file. All the DXF files to be merged must have a common origin point.

When you select Merge Vector, a standard Windows Load dialogue box appears. Select a DXF file to merge and click on OK. The DXF file you have selected will appear on the screen with the existing vectors.

Merge Vector is especially useful for joining different DXF files that have been created from one raster image that Scan2CAD has “tiled”. If you load a very large raster image into Scan2CAD (one that exceeds 32,000 pixels in the X or Y direction), Scan2CAD will automatically split it into smaller more manageable “tiles”. These tiles need to be converted separately and then joined back together again after conversion. You can either join the separate DXF files that are created back together in your CAD program - this should be easy to do in any good CAD program  - or you can merge the DXF files back together in Scan2CAD.

If you are going to merge the DXF files back together in Scan2CAD, we suggest the following procedure:

1.	Convert each tile separately and save it using Save As DXF in the File Menu. Name each tile using the tile number, e.g. Tile1.Dxf, Tile2.Dxf etc.

2.	When you have converted all the tiles, use Close Raster and Close Vector in the File Menu to close any open raster or vector files.

3.	Open Tile1.Dxf using Open Vector File in the File Menu.

4.	Now use Merge Vector to merge Tile2.Dxf and any other DXF tiles into Tile1.Dxf.

5.	Use Save As DXF in the File Menu to save the complete DXF image under a new name.

6.	If you want to scale the DXF file before importing it into your CAD program, do it now using Scale Vectors in the File Menu and then save the file again.


Save DXF (File Menu)

Save DXF saves the vector file under the vector file name shown in the Title Bar at the top of the screen.

Before you use Save DXF you should use Save As DXF to save the vector file under a specific name. If you do not do this, Scan2CAD will save the vector file under the name Untitled.Dxf. This will overwrite any other file called Untitled.Dxf.


Save As DXF (File Menu)

Save As DXF saves the vector file under a name you specify. Before using Save As DXF:

•	Make sure that individual lines are joined as polylines if this is how you want them in your CAD program. See Make Polylines.

•	Scale the vectors - see Scale Vector. You can also do this in your CAD program.

When you select Save As DXF, a standard Windows Save dialogue box appears. Type a name for the file into the File Name part of the dialogue box and click on OK.

The DXF file created by Scan2CAD will contain the following layers:

TEXT contains text (magenta).

LINE contains lines, arcs and circles (red).

POLY contains polylines (green).

Once you have saved the file it will be ready to read it into your CAD program.


Close Vector (File Menu)

Close Vector closes the vector file. It does not close the raster file if there is one open and it does not exit Scan2CAD.


Auto Save Vector (File Menu)

If Auto Save Vector is set to 10, 20 or 30 Scan2CAD automatically saves the vector file every 10, 20 or 30 minutes. If Auto Save Vector is set to 0, Scan2CAD does not automatically save the vector file.

Auto Save Vector saves the file under the file names Autobak1.dxf and Autobak2.dxf on a rotating basis.


Scale Vectors (File Menu)

•	NOTE: Scale Vectors should be the last thing you do before saving your DXF file and importing it into your CAD program. If you use Scale Vectors to scale a DXF file using fractional scale factors and you read it back into Scan2CAD using Open Vector File or Merge Vector, the DXF file may not display properly.

•	NOTE: When you exit the Scale Vectors dialogue box you will not see anything happening on the screen. However, when you save the DXF file using Save As DXF in the File Menu, the file will be saved at the correct scale and in the correct units.

When you scan a drawing and convert it, it is unlikely to appear in your CAD program at the correct scale. This is because your scanner scans the drawing in units of measure called pixels, whereas your CAD program uses millimetres or inches etc.

If the drawing you have scanned contains a line of known length, it should be quick and easy to scale the drawing to the right size in any good CAD program. However, you can also scale drawings in Scan2CAD using Scale Vectors.

Example 1

Suppose you scan in a square that is 10mm x 10mm in size. It is drawn at a scale of 1:1, so it is 10mm x 10mm both on the piece of paper you are scanning and in real life. It has been scanned in at a resolution of 300dpi.

In Scan2CAD, convert the square to vectors. Then go to Scale Vectors.

In the Scale field, type 1 so that the Scale reads 1:1.000 - the scale of the original drawing.

Some raster files contain dpi information. If your raster file contains dpi information, Scan2CAD will automatically insert the correct information into the Raster Resolution DPI field. If the value in the DPI field is 0, you need to enter the resolution you scanned the drawing in at manually. In this example, you would type 300.

In the Measurement Units field, select the units your CAD program reads drawings in. For example, if you are going to read the DXF file into your CAD program in millimetres, that is what you should choose. It is very important that you select the correct units or the size of the square in your CAD program will be wrong.

Now use Save As DXF in the File Menu to save the vector file, and load it into your CAD program. If you measure the square using your CAD program’s measure tools it should measure approximately 10mm x 10mm.

Example 2

Suppose you scan in a square that is 10mm x 10mm in size. It is drawn at a scale of 1:50, so it is 10mm x 10mm on the piece of paper you are scanning but in real life it measures 500mm x 500mm. It has been scanned in at a resolution of 300dpi.

In Scan2CAD, convert the square to vectors. Then go to Scale Vectors.

In the Scale field, type 50 so that the Scale reads 1:50.000 - the scale of the original drawing.

Some raster files contain dpi information. If your raster file contains dpi information, Scan2CAD will automatically insert the correct information into the Raster Resolution DPI field. If the value in the DPI field is 0, you need to enter the resolution you scanned the drawing in at manually. In this example, you would type 300.

In the Measurement Units field, select the units your CAD program reads drawings in. For example, if you are going to read the DXF file into your CAD program in millimetres, that is what you should choose. It is very important that you select the correct units or the size of the square in your CAD program will be wrong.

Now use Save As DXF in the File Menu to save the vector file, and load it into your CAD program. If you measure the square using your CAD program’s measure tools it should measure approximately 500mm x 500mm.


Save Text File (File Menu)

Save Text File saves all the vector text in the vector file as an ASCII text file that you can edit in any text editor like Windows Notepad, or in any word processing program.

When you select Save Text File, a standard Windows Save dialogue box appears. Type a name for the text file into the File Name part of the dialogue box and click on OK.


Exit (File Menu)

Exit closes Scan2CAD.


View Menu

The functions in the View Menu control what you see on the screen.

Window Mode

View Raster File

View Vector File

View Both Files

Zoom

Extents

Redraw

Fill

In

Out

Previous

Cursor Type

Pointer

Guide Line

View Line Colours

View Grab Points

Line, Arc, Circle, Text

Polyline

Grab Point Size

View Text Extents


Window Mode (View Menu)

W

When you are in Window Mode, the cursor looks like this when you move it over an image: .  Window Mode lets you:

•	Select part of a raster file for vectorisation or manipulation (Outline Image, Speckle Removal, Hole Removal, Thin Image or Ortho Thin Image).

•	Select an area of an image to zoom into.

•	Select part of a raster file to save as a new raster image.

Selecting part of a raster file for vectorisation or manipulation

1.	If the cursor is not in Window Mode [image], click on [image], press the W key or choose Window Mode from the View Menu.

2.	Drag a rectangle around the area you want to vectorise or manipulate (drag top left to bottom right). The area you have selected will be marked by a dotted rectangle. If you are not satisfied with your selection simply drag another rectangle.

3.	If you are vectorising the image, select appropriate OCR settings and/or vectorisation settings, then choose a conversion option. Only the selected area will be vectorised.

If you are manipulating the image select one of the following options from the Edit Raster Menu: Outline Image, Speckle Removal, Hole Removal, Thin Image, Ortho Thin Image or Thicken Image. Only the selected area will be affected by the option you choose.

After vectorisation or manipulation you will be zoomed into the area you selected. To zoom back out so you can see the whole image, press the Home key. Click here for other zoom options.

Selecting an area to zoom into

1.	If the cursor is not in Window Mode [image], click on [image], press the W key or choose Window Mode from the View Menu.

2.	Drag a rectangle around the area you want to zoom into (drag top left to bottom right). The area you have selected will be marked by a dotted rectangle. If you are not satisfied with your selection simply drag another rectangle.

3.	Press * on your numeric keypad to zoom into the selected area. What is displayed in the selected area (raster, vector or both images) depends on which icon ( [image], [image] or [image]) is currently depressed. Alternatively, use:

 or R on your keyboard to zoom in and view the raster file only.

 or V on your keyboard to zoom in and view the vector file only.

 or B on your keyboard to zoom in and view both files.

If the icon you want to use ( [image], [image] or [image])  is already depressed you can still click on it to display the view you want.

When you select an area to zoom into, Scan2CAD zooms into the exact area you have selected. No additional part of the image is displayed. You can increase the amount of image that is displayed to fill the screen using Fill.

To zoom back out so you can see the whole image, press the Home key. Click here for other zoom options.

•	NOTE: If you vectorise the raster file when you are zoomed in, only the displayed part of the image will be vectorised. If you use Outline Image, Speckle Removal, Hole Removal, Curve Thin Image, Ortho Thin Image or Thicken Image from the Edit Raster Menu only the displayed area will be affected.

Selecting part of a raster file to save as a new raster image

1.	If the cursor is not in Window Mode [image], click on [image], press the W key or choose Window Mode from the View Menu.

2.	Drag a rectangle around the area of the raster image you want to save (drag top left to bottom right). The area you have selected will be marked by a dotted rectangle. If you are not satisfied with your selection simply drag another rectangle.

3.	Select Save Raster Part As from the File Menu. Only the selected area of the raster image will be saved.

After you have used Save Raster Part As, you will be zoomed in to the area you selected. To zoom back out so you can see the whole image, press the Home key. Click here for other zoom options.


View Raster File (View Menu)

R

•	Switches off the vector file so that only the raster file is displayed on the screen.

•	Zooms into an area you have selected using Window Mode and displays the raster image only in the zoomed area. You can click on [image] to zoom in even if [image] is already depressed.

Raster files are displayed in black and white. Scan2CAD converts the black areas of the image. Negative Image in the Edit Raster Menu reverses the image so that black areas become white and white areas become black.

See also:

View Vector File

View Both Files

Redraw


View Vector File (View Menu)

V

•	Switches off the raster image so that only vectors are displayed on the screen.

•	Zooms into an area you have selected using Window Mode and displays the vector file only in the zoomed area. You can click on [image] to zoom in even if [image] is already depressed.

•	Redraws the screen so that grey lines representing the old positions of edited or deleted vectors disappear. You can click on [image] to redraw in even if [image] is already depressed. After redrawing, only vectors will be displayed in the redrawn view until you choose View Raster File or View Both Files.

Vector colours

Vectors are displayed in red unless View Line Colours in the View Menu is ticked. In this case:

Lines are displayed in red.

Polylines are displayed in green.

Arcs are displayed in magenta.

Circles are displayed in blue.

C on your keyboard toggles View Line Colours on and off.

Vector text is displayed in magenta unless you have set Display Mode in OCR Settings to Chars.

Grab points

If Line, Arc, Circle, Text in View Grab Points in the View Menu is ticked, the following grab points are displayed as squares: vector end points, circle centre points, text origin points, arc mid points and circle 12 o’clock points. Vector end points, circle centre points and text origin points are shown as blank squares. Arc mid points and circle 12 o’clock points are shown as grey filled squares. The size of the squares is controlled by Grab Point Size in the View Menu.

G on your keyboard toggles grab point squares on and off.

Polyline end points

If Polyline in View Grab Points in the View Menu is ticked, polyline end points are displayed as green filled squares. The size of the squares is controlled by Grab Point Size in the View Menu.

P on your keyboard toggles polyline end point squares on and off.

Text extents

If View Text Extents in the View Menu is ticked, text that has been recognised using OCR is surrounded by a dashed box.

T on your keyboard toggles text extent boxes on and off.

See also

View Raster File

View Both Files

Redraw


View Both Files (View Menu)

B

•	Switches on both the raster and vector files so that the vector file is displayed superimposed over the raster file.

•	Zooms into an area you have selected using Window Mode and displays both the raster and vector images in the zoomed area. You can click on [image] to zoom in even if [image] is already depressed.

•	Redraws the screen so that grey lines representing the old positions of edited or deleted vectors disappear. You can click on [image] to redraw in even if [image] is already depressed.

See View Raster File and View Vector File for details on what is displayed when you are viewing raster and vector files.

See also Redraw.


Zoom (View Menu)

Extents

Redraw

Fill

In

Out

Previous


Extents (Zoom - View Menu)

Home key

Zooms out so you can see the whole image. What is displayed (raster, vector or both images) depends on which icon ( [image], [image] or [image]) is currently depressed.

See also zooming.


Redraw (Zoom - View Menu)

* on numeric keypad

•	Redraws the screen so that grey lines representing the old positions of edited or deleted vectors disappear.

•	Zooms into an area you have selected using Window Mode.

What is displayed after the refresh or zoom (raster, vector or both images) depends on which icon ( [image], [image] or [image])  is currently depressed.

See also:

View Raster File

View Vector File

View Both Files


Fill (Zoom - View Menu)

F, / on numeric keypad or Fill Box

Where a zoomed view only takes up part of the screen, Fill increases the amount of the image that is displayed to fill the screen. Subsequent uses of Fill shrink what is displayed slightly so you can see more of the image on the screen.

For example, suppose you choose to zoom into the area enclosed in the magenta rectangle below:

Only the exact area you have chosen will be displayed on the screen:

If you use Fill by pressing F on your keyboard, / on the numeric keypad or by double clicking in the Fill Box, the zoomed area will be expanded to fill the screen:

If you use Fill again, the view will shrink slightly. For example, if you use Fill several times the top point of the gable, just off the screen in the illustration above, will appear on the screen:


In (Zoom - View Menu)

M or + on the numeric keypad

 and + zoom in (magnify) around the screen centre.

M zooms in (magnifies) around the current cursor position.

What is displayed (raster, vector or both images) depends on which icon ( [image], [image] or [image]) is currently depressed.

See also zooming.


Out (Zoom - View Menu)

D or - on the numeric keypad

 and - zoom out (demagnify) around the screen centre.

D  zooms out (demagnifies) around the current cursor position.

What is displayed (raster, vector or both images) depends on which icon ( [image], [image] or [image]) is currently depressed.

See also zooming.


Previous (Zoom - View Menu)

Delete key or right mouse button double click

Steps back through the last ten zooms you have used, one at a time. What is displayed (raster, vector or both images) depends on which icon ( [image], [image] or [image]) is currently depressed.

See also zooming.


Cursor Type (View Menu)

Pointer

Guide Line


Pointer (Cursor Type - View Menu)

When Pointer is ticked, the cursor changes to the shape below when you are drawing, erasing or editing entities on the raster or vector image. The square at the tip of the cursor is the size of one pixel on the image.

If you are drawing on the raster image or erasing from it, an outer square shows the size of the pen or eraser. The pen/eraser size is set in Pen Size in the Edit Raster Menu and can be anything from 1x1 to 5x5 pixels in size:

If you are editing vectors, an outer square shows the Grab Snap Distance. The vector or grab point you are editing must be within this square. Grab Snap Distance is set in Grab Snap Distance in the Edit Vector Menu or by pressing the 0, 1, 2, 4 or 8 number keys (the ones above QWERTY) on your  keyboard. This sets the snap distance to 0, 1, 2, 4 or 8 pixels respectively:

When you are zoomed out, you won’t be able to see the squares at the tip of the cursor:

See also Guide Line.


Guide Line (Cursor Type - View Menu)

When Guide Line is ticked, the cursor changes to cross hairs that extend all the way across the screen. A square at the centre of the cross hairs is the size of one pixel on the image.

If you are drawing on the raster image or erasing from it, an outer square shows the size of the pen or eraser. The pen/eraser size is set in Pen Size in the Edit Raster Menu and can be anything from 1x1 to 5x5 pixels in size:

If you are editing vectors, an outer square shows the Grab Snap Distance. The vector or grab point you are editing must be within this square. Grab Snap Distance is set in Grab Snap Distance in the Edit Vector Menu or by pressing the 0, 1, 2, 4 or 8 number keys (the ones above QWERTY) on your  keyboard. This sets the snap distance to 0, 1, 2, 4 or 8 pixels respectively:

When you are zoomed out, you won’t be able to see the squares at the cross-hair centre:

See also Pointer.


View Line Colours (View Menu)

C

Vectors are displayed in red unless View Line Colours is ticked. In this case:

Lines are displayed in red.

Polylines are displayed in green.

Arcs are displayed in magenta.

Circles are displayed in blue.

C on your keyboard toggles View Line Colours on and off.

Vector text is always displayed in magenta unless you have set Display Mode in OCR Settings to Chars.


View Grab Points (View Menu)

Line, Arc, Circle, Text

Polyline


Line, Arc, Circle, Text (View Grab Points - View Menu)

G

If Line, Arc, Circle, Text is ticked, the following grab points are displayed as squares: vector end points, circle centre points, text origin points, arc mid points and circle 12 o’clock points. Vector end points, circle centre points and text origin points are shown as blank squares. Arc mid points and circle 12 o’clock points are shown as grey filled squares. The size of the squares is controlled by Grab Point Size in the View Menu.

You can manipulate the grab points using the functions in the Edit Vector Menu.

See also Polyline.


Polyline (View Grab Points - View Menu)

P

If Polyline is ticked, polyline end points are displayed as green filled squares. The size of the squares is controlled by Grab Point Size in the View Menu.

You can move the polyline end points using the functions in the Edit Vector Menu.

See also Line, Arc, Circle, Text.


Grab Point Size  (View Menu)

Grab Point Size Controls the size of grab points when these are displayed on the screen.


View Text Extents  (View Menu)

T

When OCR recognises something on the drawing as text, it masks that part of the drawing. If you subsequently vectorise the drawing, Scan2CAD will not attempt to vectorise the masked area.

If OCR has incorrectly recognised something on the drawing as text and you delete the text it has created, this area will no longer be masked. If you now vectorise the drawing, the area that Scan2CAD previously recognised as text will be vectorised as lines and arcs.

When View Text Extents is ticked, Scan2CAD shows masked areas by placing dashed boxes around text that has been recognised by OCR.


Edit Raster Menu

The Edit Raster Menu contains functions for tidying up the raster file.

Pen Size

Raster Draw Mode

Raster Erase Mode

Line

Ortho

Rectangle

Circle

Arc

Freehand

Point

Area

Negative Image

Rotate Image by Degrees

Rotate Image by Line

Scale Image

Outline Image

Speckle Removal

Hole Removal

Thin Image

Ortho Thin Image

Thicken Image

Undo


Pen Size (Edit Raster Menu)

Pen Size ranges from 1x1 to 5x5 pixels and is the size of the pen used to draw and erase entities on the raster image.

When you are drawing or erasing raster entities, the pen size is shown by the outer square around the cursor pointer or cross hairs - the inner square is the size of one pixel on the image:

 or

When you are zoomed out, these squares will probably be too small to see.


Raster Draw Mode (Edit Raster Menu)

When you are in Raster Draw Mode you can draw on the raster image.  To draw on the raster image follow the steps below. Steps 1 and 2 are not necessary if Pen Size and Raster Draw Mode are already selected.

1.	Choose the correct Pen Size using Pen Size in the Edit Raster Menu.

2.	Click on [image] to select Raster then click on [image] to select Draw Mode, or tick the Raster Draw Mode option in the Edit Raster Menu.

3.	Click on one of the following icons, or select the relevant function from the Edit Raster Menu:

 Line

 Ortho Line

 Rectangle

 Circle

 Arc

 Freehand

 Point

 Area

4.	Draw the entity, which will  be drawn in black.

5.	If you are not happy with the entity, click on [image] to undo it.

•	NOTE: If you are making important changes to the raster image, don’t forget to save it frequently using Save As Raster or Save Raster in the File Menu! Alternatively, set Auto Save Raster in the File Menu.


Raster Erase Mode (Edit Raster Menu)

When you are in Raster Erase Mode you can erase items from the raster image. Items are erased from the raster image by drawing over them in white. To erase from the raster image:

1.	Choose the correct Pen Size using Pen Size in the Edit Raster Menu.

2.	Click on [image] to select Raster then click on [image] to select Erase Mode, or tick the Raster Erase Mode option in the Edit Raster Menu.

3.	Click on one of the following icons, or select the relevant function from the Edit Raster Menu:

 Line

 Ortho Line

 Rectangle

 Circle

 Arc

 Freehand

 Point

 Area

4.	Erase the entity. This is exactly the same as drawing the entity except that it will be drawn in white, effectively erasing any black areas underneath.

5.	If you are not happy with what you have erased, click on [image] to undo it.

•	NOTE: If you are making important changes to the raster image, don’t forget to save it frequently using Save As Raster or Save Raster in the File Menu! Alternatively, set Auto Save Raster in the File Menu.


Line (Edit Raster Menu)

Line draws or erases lines.

The steps for drawing and erasing lines on a raster image are as described in Raster Draw Mode and Raster Erase Mode. To draw or erase a line (step 4), position the cursor at the line's start point. Press down your left mouse button. Holding down your left mouse button, move your mouse. As you move your mouse you will see the line being drawn. When you are satisfied with the line, raise your left mouse button. If you are drawing, the line will be drawn in black. If you are erasing, it will be drawn in white.

To draw or erase lines on the vector image, see Line.


Ortho Line (Edit Raster Menu)

Ortho Line is exactly the same as Line except that it only draws or erases horizontal and vertical lines.


Rectangle (Edit Raster Menu)

Rectangle draws or erases rectangles.

The steps for drawing and erasing rectangles on a raster image are as described in Raster Draw Mode and Raster Erase Mode. To draw or erase a rectangle (step 4), position the cursor at one of the rectangle's corners. Press down your left mouse button. Holding down your left mouse button, move your mouse. As you move your mouse you will see the rectangle being drawn. When you are satisfied with the rectangle, raise your left mouse button. If you are drawing, the rectangle will be drawn in black. If you are erasing, the rectangle will be drawn in white.

To draw or erase rectangles on the vector image, see Rectangle.


Circle (Edit Raster Menu)

Circle draws or erases circles.

The steps for drawing and erasing circles on a raster image are as described in Raster Draw Mode and Raster Erase Mode. To draw or erase a circle (step 4), position the cursor at a point on the circle's circumference. Press down your left mouse button. Holding down your left mouse button, move your mouse. As you move your mouse you will see the circle being drawn. When you are satisfied with the circle, raise your left mouse button. If you are drawing, the circle will be drawn in black. If you are erasing, the circle will be drawn in white.

To draw or erase circles on the vector image, see Circle.


Arc (Edit Raster Menu)

Arc draws or erases arcs.

The steps for drawing and erasing arcs on a raster image are as described in Raster Draw Mode and Raster Erase Mode. To draw or erase an arc (step 4), position the cursor at the first point of the arc.

Press down your left mouse button. Holding down your left mouse button, move your mouse to a point on the arc. A line will appear between the first point of the arc and the point on the arc. Raise your left mouse button.

Then press down your left mouse button again. Holding down your left mouse button, move your mouse to the end point of the arc. As you move your mouse you will see the arc being drawn. When you are satisfied with the arc, raise your left mouse button.

If you are drawing, the arc will be drawn in black. If you are erasing, the arc will be drawn in white.

To draw or erase arcs on the vector image, see Arc.


Freehand (Edit Raster Menu)

Freehand allows you to draw freehand sketches on, or erase freehand sketches from, an image.

The steps for drawing and erasing sketches on a raster image are as described in Raster Draw Mode and Raster Erase Mode. To draw or erase a sketch (step 4), position the cursor at the start of the freehand sketch and press down your left mouse button. Holding down your left mouse button, move your mouse. As you move your mouse, the freehand sketch will be drawn. When you have finished, raise your left mouse button. If you are drawing, the sketch will be drawn in black. If you are erasing, the sketch will be drawn in white.

To draw or erase freehand sketches on a vector image, see Freehand.


Point (Edit Raster Menu)

Point draws or erases points.

The steps for drawing and erasing points on a raster image are as described in Raster Draw Mode and Raster Erase Mode. To draw or erase a point (step 4), position the cursor where you want the point to be and click. The point will be drawn. If you are drawing, the point will be drawn in black. If you are erasing, it will be drawn in white.

To draw or erase points on a vector image, see Point.


Area (Edit Raster Menu)

Area draws rectangular solid areas on, or erase them from, raster images. It is very useful for quickly deleting areas of the raster file.

The steps for drawing and erasing areas on a raster image are as described in Raster Draw Mode and Raster Erase Mode. To draw or erase an area (step 4), position the cursor at one of the area's corners. Press down your left mouse button. Holding down your left mouse button, move your mouse. As you move your mouse you will see a rectangle being drawn. When you are satisfied with the rectangle, raise your left mouse button. If you are drawing, the rectangle will be drawn and filled in black. If you are erasing, the rectangle will be drawn and filled in white.

To erase areas from a vector image, see Vector Erase Mode.


Negative Image (Edit Raster Menu)

Negative Image converts the black parts of a raster image to white and the white parts to black. It operates on the entire image.

Some scanning software produces negative images of the original drawing, i.e. white lines on a black background. Scan2CAD converts positive images, i.e. black lines on a white background. Before you can vectorise a negative image in Scan2CAD you must use Negative Image to change the image to positive.


Rotate Image by Degrees (Edit Raster Menu)

Rotate Image by Degrees rotates or “deskews” a raster image by a user-defined number of degrees. It operates on the entire image.

When you select Rotate Image by Degrees, a dialogue box appears. Enter the number of degrees you want to rotate the image by into the dialogue box.  If you enter a positive angle, the image will be rotated in a clockwise direction. If you enter a negative angle, it will be rotated in an anti clockwise direction. You can enter fractions of a degree (e.g. 0.5).

The Rotate Image by Degrees facility is intended to correct small skews caused by scanning the drawing in at a slight angle (up to 3°) or to rotate the image by 90° or 180°. If you rotate the image at any other angle it will undergo a severe deterioration in quality.

See also Rotate Image by Line.


Rotate Image by Line (Edit Raster Menu)

[Ctrl]+L

Rotate Image by Line automatically “deskews” a raster image using a reference line. It operates on the entire image.

When you select Rotate Image by Line, Scan2CAD prompts you to draw a reference line.

Draw a reference line on top of a line on your raster image that should be exactly horizontal or vertical. Draw the reference line by pressing down your left mouse button, holding it down and then moving your mouse.

Scan2CAD will automatically rotate the image so that the line you drew the reference line over is exactly horizontal or vertical.

The Rotate Image by Line facility is intended to correct small skews caused by scanning the drawing in at a slight angle (up to 3°). If you rotate the image at larger angles it may undergo a severe deterioration in quality.

See also Rotate Image by Degrees.


Scale Image (Edit Raster Menu)

Scale Image increases or decreases the size of the raster image. It operates on the entire image.

When you select Scale Image, a dialogue box appears. Type in X and Y scale factors. If you type in scale factors of 0.5 and 0.5 the raster image will be halved in size. If you type in scale factors of 2 and 2 the raster image will be doubled in size etc.

Scaling a raster image can result in a deterioration of image quality.


Outline Image (Edit Raster Menu)

Outline Image deletes solid black areas of pixels from the raster image to leave an outline. It only affects the part of the image that is currently displayed on the screen. Choose the part of the image you want to outline by zooming into it or by selecting it using Window Mode.

When you select Outline Image, a dialogue box appears. Enter the thickness in pixels that you want the remaining raster outlines to be after the solid areas have been removed.

Click on [image] to undo Outline Image.


Speckle Removal (Edit Raster Menu)

Speckle Removal cleans up the raster image by removing black speckles from it. It only affects the part of the image that is currently displayed on the screen. Choose the part of the image you want to despeckle by zooming into it or by selecting it using Window Mode.

When you select Speckle Removal, a dialogue box appears. Enter a number of pixels into the Pixels Speckle Size box and click on OK. All speckles that are smaller than the number of pixels you have entered and that are totally surrounded by white pixels will be removed from the raster image.

Click on [image] to undo Speckle Removal.

See also:

Area, which you can use to delete areas of dirt or speckles.

Hole Removal, which removes white speckles from black areas.


Hole Removal (Edit Raster Menu)

Hole Removal cleans up the raster image by removing white speckles from black areas of the image. It only affects the part of the image that is currently displayed on the screen. Choose the part of the image you want to remove holes from by zooming into it or by selecting it using Window Mode.

When you select Hole Removal, a dialogue box appears. Enter a number of pixels into the Pixels Hole Size box and click on OK. All holes that are smaller than the number of pixels you have entered and that are totally surrounded by black pixels will be removed from the raster image.

Click on [image] to undo Hole Removal.

See also:

Thicken Image, which can also be useful for removing holes.

Speckle Removal, which removes black speckles from white areas.


Thin Image (Edit Raster Menu)

Thin Image thins the raster image, with a bias towards retaining the curves. It only affects the part of the image that is currently displayed on the screen. Choose the part of the image you want to thin by zooming into it or by selecting it using Window Mode.

When you select Thin Image a dialogue box appears. Enter the Number of Thinnings and click on OK. The Number of Thinnings is the number of times Scan2CAD will go through the image stripping a layer of pixels off it. The larger the number you type, the more thinned the image will be although it will never be thinned right away - Scan2CAD will always retain an image one pixel thick.

Click on [image] to undo Thin Image.

See also Ortho Thin Image.


Ortho Thin Image (Edit Raster Menu)

Ortho Thin Image thins the raster image, with a bias towards retaining orthogonal lines. It only affects the part of the image that is currently displayed on the screen. Choose the part of the image you want to thin by zooming into it or by selecting it using Window Mode.

When you select Ortho Thin Image a dialogue box appears. Enter the Number of Thinnings and click on OK. The Number of Thinnings is the number of times Scan2CAD will go through the image stripping a layer of pixels off it. The larger the number you type, the more thinned the image will be although it will never be thinned right away - Scan2CAD will always retain an image one pixel thick.

Click on [image] to undo Ortho Thin Image.

See also Thin Image.


Thicken Image (Edit Raster Menu)

Thicken Image thickens the raster image as follows. If it finds lines on the image that are one pixel wide it adds two extra pixels, one on either side. If it finds lines on the image that are two pixels wide it adds one extra pixel. Thicken Image is useful because a thicker raster image will often give a smoother vector result than a very thin raster image.

Thicken Image only affects the part of the image that is currently displayed on the screen. Choose the part of the image you want to thicken by zooming into it or by selecting it using Window Mode.

Click on [image] to undo Thicken Image.


Undo (Edit Raster Menu)

Undo undoes the following raster editing operations:

Line, Ortho Line, Rectangle, Circle, Arc, Freehand, Point, Area, Outline Image, Speckle Removal, Hole Removal, Curve Thin Image, Ortho Thin Image and Thicken Image.

Undo undoes your last action only.

See also Undo.


Edit Vector Menu

The Edit Vector Menu contains functions for tidying up the vector file.

Vector Draw Mode

Vector Erase Mode

Line

Ortho Line

Rectangle

Circle

Arc

Freehand

Point

Area

Text

Grab Snap Distance

Attach Grab Points

Move Grab Point

Move Grab Point Ortho

Split Line

Join Vectors

Curve to Line

Line to Curve

Query Vector

Make Polylines

Un-Make Polylines

Undo


Vector Draw Mode (Edit Vector Menu)

When you are in Vector Draw Mode you can draw vectors onto the vector image. To draw vectors, follow the steps below. Step 1 is not necessary if  Vector Draw Mode is already selected.

1.	Click on [image] to select Vector then click on [image] to select Draw Mode, or tick the Vector Draw Mode option in the Edit Vector Menu.

2.	Click on one of the following icons, or select the relevant function from the Edit Vector Menu:

 Line

 Ortho Line

 Rectangle

 Circle

 Arc

 Freehand

 Point

 Text

3.	Draw the vector. The colour of the vector that is drawn is controlled by View Line Colours in the Edit Menu. If you are drawing text, the colour of the text is controlled by Display Mode in OCR Settings.

4.	If you are not happy with the vector you have drawn, click on [image] to undo it.

•	NOTE: If you are making important changes to the vector image, don’t forget to save it frequently using Save As DXF or Save DXF in the File Menu! Alternatively, set Auto Save Vector in the File Menu.


Vector Erase Mode (Edit Vector Menu)

When you are in Vector Erase Mode you can erase vectors from the vector image. You can either erase vectors by clicking on the vectors you want to erase, or you can erase all the vectors in an area. To erase vectors, follow the steps below.

To erase vectors by clicking on them

Step 1 is not necessary if  Vector Erase Mode is already selected.

1.	Click on [image] to select Vector then click on [image] to select Erase Mode, or tick the Vector Erase Mode option in the Edit Vector Menu.

2.	Click on one of the following icons, or select the relevant function from the Edit Vector Menu:

 Line

 Ortho Line

 Rectangle

 Circle

 Arc

 Freehand

 Point

 Text

3.	Click on the vectors to delete. As you click on each vector, it turns grey.

To delete vector text, click on the text’s grab point or on the text itself.

4.	Redraw the screen by pressing * on your numeric keypad. This will redraw the current view - raster, vector or both images - depending on which icon ( [image], [image] or [image]) is currently depressed. Alternatively, use:

 or R on your keyboard to redraw the raster file only.

 or V on your keyboard to redraw the vector file only.

 or B on your keyboard to redraw both files.

If the icon you want to use ( [image], [image] or [image]) is already depressed you can still click on it to redraw the view you want.

5.	To undelete vectors, click on [image].

•	NOTE: If you are making important changes to the vector image, don’t forget to save it frequently using Save As DXF or Save DXF in the File Menu! Alternatively, set Auto Save Vector in the File Menu.

To erase all the vectors in an area

Step 1 is not necessary if Vector Erase Mode is already selected.

1.	Click on [image] to select Vector then click on [image] to select Erase Mode, or tick the Vector Erase Mode option in the Edit Vector Menu.

2.	Click on [image], or select Area from the Edit Vector Menu.

3.	Drag a rectangle around the vectors you want to delete. The vectors in the rectangle will turn grey. Only vectors wholly enclosed in the rectangle will be deleted.

Text will be deleted if its grab point is enclosed. G on your keyboard toggles grab point display on and off. When grab point display is on, the text grab point is shown as a square at the bottom left of the text.

4.	Redraw the screen, as in step 4 above.

5.	You cannot undelete vectors that have been deleted using area delete.

•	NOTE: If you are making important changes to the vector image, don’t forget to save it frequently using Save As DXF or Save DXF in the File Menu! Alternatively, set Auto Save Vector in the File Menu.


Line (Edit Vector Menu)

Line draws a line or lets you erase any vector by clicking on it.

The steps for drawing lines on a vector image are as described in Vector Draw Mode. To draw the line (step 3), position the cursor at the line's start point. Press down your left mouse button. Holding down your left mouse button, move your mouse. As you move your mouse you will see the line being drawn. When you are satisfied with the line, raise your left mouse button.

The steps for erasing vectors using the Line function are as described in Vector Erase Mode.

To draw or erase lines on the raster image, see Line.


Ortho Line (Edit Vector Menu)

Ortho Line is exactly the same as Line except that it only draws horizontal and vertical lines.


Rectangle (Edit Vector Menu)

Rectangle draws a rectangle or lets you erase any vector by clicking on it. Rectangles are drawn as polylines.

The steps for drawing rectangles on a vector image are as described in Vector Draw Mode. To draw the rectangle (step 3), position the cursor at one of the rectangle's corners. Press down your left mouse button. Holding down your left mouse button, move your mouse. As you move your mouse you will see the rectangle being drawn. When you are satisfied with the rectangle, raise your left mouse button.

The steps for erasing vectors using the Rectangle function are as described in Vector Erase Mode.

To draw or erase rectangle on the raster image, see Rectangle.


Circle (Edit Vector Menu)

Circle draws a circle or lets you erase any vector by clicking on it.

The steps for drawing circles on a vector image are as described in Vector Draw Mode. To draw the circle (step 3), position the cursor at a point on the circle's circumference. Press down your left mouse button. Holding down your left mouse button, move your mouse. As you move your mouse you will see the circle being drawn. When you are satisfied with the circle, raise your left mouse button.

The steps for erasing vectors using the Circle function are as described in Vector Erase Mode.

To draw or erase circles on the raster image, see Circle.


Arc (Edit Vector Menu)

Arc draws an arc or lets you erase any vector by clicking on it.

The steps for drawing arcs on a vector image are as described in Vector Draw Mode. To draw the arc (step 3), position the cursor at the first point of the arc.

Press down your left mouse button. Holding down your left mouse button, move your mouse to a point on the arc. A line will appear between the first point of the arc and the point on the arc. Raise your left mouse button.

Then press down your left mouse button again. Holding down your left mouse button, move your mouse to the end point of the arc. As you move your mouse you will see the arc being drawn. When you are satisfied with the arc, raise your left mouse button.

The steps for erasing vectors using the Arc function are as described in Vector Erase Mode.

To draw or erase arcs on the raster image, see Arc.


Freehand (Edit Vector Menu)

Freehand allows you to draw freehand sketches or to erase any vector by clicking on it. Freehand sketches are drawn as polylines.

The steps for drawing a sketch on a vector image are as described in Vector Draw Mode. To draw the sketch (step 3), position the cursor at the start of the freehand sketch and press down your left mouse button. Holding down your left mouse button, move your mouse. As you move your mouse, the freehand sketch will be drawn. When you have finished, raise your left mouse button.

The steps for erasing vectors using the Freehand function are as described in Vector Erase Mode.

To draw or erase freehand sketches on the raster image, see Freehand.


Point (Edit Vector Menu)

Point draws a point or lets you erase any vector by clicking on it.

The steps for drawing a point on a vector image are as described in Vector Draw Mode. To draw the point (step 3), position the cursor where you want the point to be and click. The point will be drawn.

The steps for erasing vectors using the Point function are as described in Vector Erase Mode.

To draw or erase points on the raster image, see Point.


Area (Edit Vector Menu)

Area deletes vectors within a rectangle as described in Vector Erase Mode.

You cannot undelete vectors that have been deleted using area delete.

To draw or erase areas on the raster image, see Area.


Text (Edit Vector Menu)

Text draws text, edits text or lets you erase any vector by clicking on it.

The steps for erasing vectors using the Text function are as described in Vector Erase Mode.

To use Text to draw or edit text:

1.	Click on [image] or Text in the Vector Edit Menu to select text drawing/editing. If the [image] icon is greyed out, click on [image] to select Edit Vector.

2.	If you are drawing text, click where you want the text to be positioned.

If you are editing text, click on the grab point of the text you want to edit or on the text itself.

3.	A dialogue box appears. This contains the following fields.

•	Type the text into the Text field, or edit the text that appears in the Text field. The text that you type in this field will appear on one line. To create another line of text, click on the New Line button. Once you have clicked on the New Line button, you cannot return to the previous line. To edit text you have entered on a previous line, click on OK to exit the dialogue box so that the text appears on the screen, then edit the text.

•	For angled text, enter an angle into the Angle field. A positive angle will rotate the text clockwise and a negative angle will rotate it anti clockwise.

•	Enter text height into the Height field. Height is measured in pixels.

•	The Origin X and Origin Y fields show the coordinates of the position you clicked on in step 2 if you are drawing text, or the coordinates of the text’s grab point if you are editing text. If you change the coordinate values in these fields, the text will be positioned at the new coordinates. The text will appear above and to the right of the coordinate position. Coordinates are measured in pixels. Coordinate 0,0 is at the top left corner of the image.

When you are satisfied with the contents of the dialogue box, click on OK.

4.	If you are not happy with the text you have drawn, click on [image] to undo it.

•	NOTE: If you are making important changes to the text, don’t forget to save the vector file frequently using Save As DXF or Save DXF in the File Menu! Alternatively, set Auto Save Vector in the File Menu.


Grab Snap Distance (Edit Vector Menu)

0, 1, 2, 4 and 8

If you are editing vectors, an outer square around the pointer or cross hair cursor shows the Grab Snap Distance. The vector or grab point you are editing must be within the Grab Snap Distance.

  or

Set Grab Snap Distance using Grab Snap Distance in the Edit Vector Menu or by pressing the 0, 1, 2, 4 or 8 number keys (the ones above QWERTY) on your  keyboard. This sets the snap distance to 0, 1, 2, 4 or 8 pixels respectively.

When you are zoomed out, you won’t be able to see the Grab Snap Distance square around the cursor. In this case it is a good idea to zoom into the image to make sure that the vector or grab point you are trying to edit is within the Grab Snap Distance.


Attach Grab Points (Edit Vector Menu)

A

When Attach Grab Points is ticked, Move Grab Point and Move Grab Point Ortho move both vectors attached to a grab point:

When Attach Grab Points is ticked, the Status Display at the bottom of the screen reads ATON.

When Attach Grab Points is not ticked, Move Grab Point and Move Grab Point Ortho only move one vector. Which vector is moved is random unless you click on [image] and then on the vector you want to move before using Move Grab Point or Move Grab Point Ortho.

When Attach Grab Points is not ticked, the Status Display at the bottom of the screen reads ATOFF.


Move Grab Point (Edit Vector Menu)

Move Grab Point lets you move a grab point to a new position:

Where two vectors join at a grab point, Move Grab Point will either move both vectors ...

... or just one vector ...

... depending on whether Attach Grab Points in the Edit Vector Menu is ticked or not.

Displaying grab points

Before using Move Grab Point it is a good idea to display grab points on the screen so that you can see exactly what you are moving.

•	G on your keyboard toggles the display of grab points on and off. Vector end points, circle centre points and text origin points are shown as blank squares. Arc mid points and circle 12 o’clock points are shown as grey filled squares. Use Grab Point Size in the View Menu to make the squares bigger or smaller.

•	P on your keyboard toggles the display of polyline end points on and off. Polyline end points are displayed as green filled squares. Use Grab Point Size in the View Menu to make the squares bigger or smaller.

Cursor type

When you are moving grab points it is a good idea to set the cursor type to Guide Line using Cursor Type in the View Menu. The Guide Line cursor type has horizontal and vertical cross hairs that extend across the screen. These are very useful for aligning grab points with other points on the drawing.

Moving grab points by dragging them

To use Move Grab Point, position the cursor at the grab point you want to move. Press down your left mouse button. Holding down your left mouse button, move your mouse. As you move your mouse you will see a line being drawn from the grab point’s current position to its new position. When you are satisfied with the grab point’s new position, raise your left mouse button. The grab point will be moved.

If you are having problems moving a grab point, this will be because the grab point you are trying to move is not within the Grab Snap Distance box around the cursor. You must either zoom into the image or increase the Grab Snap Distance.

Moving grab points by clicking

If you click your mouse when the grab point you want to move is within the Grab Snap Distance box around the cursor, the grab point will be moved to the current cursor position. Other grab points within the Grab Snap Distance will also be moved. Three examples of using Move Grab Point in this way are shown below.

Example 1: Tidying up lines.

Before using Move Grab Point:

Enclose the grab point you want to move within the Grab Snap Distance box. Place the cursor at the position you want to move the grab point to:

When you click, the grab point within the Grab Snap Distance box is moved to the cursor position and is effectively deleted:

Example 2: Tidying up overshoots.

Before using Move Grab Point:

Enclose the grab point you want to move within the Grab Snap Distance box. Place the cursor at the position you want to move the grab point to:

When you click, the grab point within the Grab Snap Distance box is moved to the cursor position:

Example 3: Tidying up corners.

Before using Move Grab Point:

Enclose the grab points you want to move within the Grab Snap Distance box. Place the cursor at the position you want to move the grab points to:

When you click, the grab points within the Grab Snap Distance box are moved to the cursor position:

If Move Grab Point does not work as expected ...

If Move Grab Point does not work as expected, make sure that the grab point you are trying to move is within the Grab Snap Distance box around the cursor. Also make sure that grab points that you don’t want to move are not within the Grab Snap Distance box. You may have to zoom into the image so that you can see what you are doing more clearly, or you may have to increase or decrease the Grab Snap Distance.

You should also check the Status Display at the bottom of the screen. If Attach Grab Points is turned off, the Status Display will read ATOFF and Move Grab Point may not move what you expected. The A key on your keyboard toggles Attach Grab Points on and off.

Redrawing the screen

When you have moved a grab point, the old position of the grab point and the vector attached to it is shown in grey. It will disappear next time you redraw the screen.

Undoing a moved grab point

Click on [image] to undo a moved grab point.

•	NOTE: If you are making important changes to the vector image, don’t forget to save it frequently using Save As DXF or Save DXF in the File Menu! Alternatively, set Auto Save Vector in the File Menu.


Move Grab Point Ortho (Edit Vector Menu)

Move Grab Point Ortho is exactly the same as Move Grab Point except when you move a grab point by a small distance, in which case you will only be able to move it horizontally and vertically.


Split Line (Edit Vector Menu)

Split Line divides a line into two and inserts a grab point at the split. It does not work on polylines or arcs.

Before using Split Line it is a good idea to display grab points on the screen. G on your keyboard toggles grab point display on and off. Use Grab Point Size in the View Menu to make these squares bigger or smaller.

To split a line, click on the line at the split position.

If you are having problems splitting a line, this will be for one of the following reasons:

•	The line you are clicking on is not under the Grab Snap Distance box around the cursor. You must either zoom into the image or increase the Grab Snap Distance.

•	The line is part of a polyline. C on your keyboard toggles vector colours on and off. If vector colours are on, polylines are displayed in green. Click on  Un-Make Polylines in the Edit Vector Menu to turn a polyline into a line so that you can split it.

•	The line is a shallow arc. C on your keyboard toggles vector colours on and off. If vector colours are on, arcs are displayed in magenta. Use Curve to Line in the Edit Vector Menu to turn an arc into a line so that you can split it.

Once you have split a line, you can use Move Grab Point or Move Grab Point Ortho to move the new grab point to another position:

Before using Split Line:

Split Line divides the line into two and inserts a grab point:

You can use Move Grab Point or Move Grab Point Ortho to move the grab point to a new position:

Click on [image] to rejoin a split line.

•	NOTE: If you are making important changes to the vector image, don’t forget to save it frequently using Save As DXF or Save DXF in the File Menu! Alternatively, set Auto Save Vector in the File Menu.


Join Vectors (Edit Vector Menu)

Join Vectors joins two vectors together and removes the grab point between them. You can join two lines, two arcs, or a line and an arc.

If you join two lines, the resultant vector will be a line.

If you join two arcs, the resultant vector will be an arc.

If you join a line and an arc, the resultant vector will be an arc.

For example:

Before using Join Vectors:

After using Join Vectors:

Before using Join Vectors. There is a short line joining the arc to the vertical line:

After using Join Vectors. The grab point between the arc and the short line has been removed. The arc and the short line have been joined to give a single arc:

Before using Join Vectors it is a good idea to display grab points on the screen. G on your keyboard toggles grab point display on and off. Use Grab Point Size in the View Menu to make these squares bigger or smaller.

To join two vectors, click on the grab point between them.

If you are having problems joining vectors, this will be for one of the following reasons:

•	The grab point you are clicking on is not within the Grab Snap Distance box around the cursor. You must either zoom into the image or increase the Grab Snap Distance.

•	One of the vectors is part of a polyline. C on your keyboard toggles vector colours on and off. If vector colours are on, polylines are displayed in green. Click on Un-Make Polylines in the Edit Vector Menu to turn a polyline into a line so that you can join it.

•	If more than two vectors are attached to the grab point you are trying to remove, Join Vectors won’t work.

When you have joined two vectors, the old positions of the vectors are shown in grey. They will disappear next time you redraw the screen.

Click on [image] to split two vectors you have just joined.

•	NOTE: If you are making important changes to the vector image, don’t forget to save it frequently using Save As DXF or Save DXF in the File Menu! Alternatively, set Auto Save Vector in the File Menu.


Curve to Line (Edit Vector Menu)

Curve to line converts a vector arc to a vector line.

Before using Curve to Line it is a good idea to display vector colours. C on your keyboard toggles vector colours on and off. If vector colours are on, arcs are displayed in magenta and lines are displayed in red.

To convert an arc to a line, click on the arc.

If you are having problems converting an arc to a line, this will be because the arc you are clicking on is not under the Grab Snap Distance box around the cursor. You must either zoom into the image or increase the Grab Snap Distance.

When you have converted an arc to a line, the original arc is shown in grey. It will disappear next time you redraw the screen.

Click on [image] to undo an arc to line conversion.

•	NOTE: If you are making important changes to the vector image, don’t forget to save it frequently using Save As DXF or Save DXF in the File Menu! Alternatively, set Auto Save Vector in the File Menu.


Line to Curve (Edit Vector Menu)

Line to curve converts a vector line to a vector arc.

Before using Line to Curve it is a good idea to display vector colours. C on your keyboard toggles vector colours on and off. If vector colours are on, arcs are displayed in magenta and lines are displayed in red.

To convert a line to an arc, click on the line. Click on the side of the line that must become the outside (convex side) of the arc.

If you are having problems converting a line to an arc, this will be for one of the following reasons:

•	The line you are clicking on is not under the Grab Snap Distance box around the cursor. You must either zoom into the image or increase the Grab Snap Distance.

•	The line is part of a polyline. If vector colours are on, polylines are displayed in green. Use Un-Make Polylines in the Edit Vector Menu to turn a polyline into a line so that you can convert it to an arc.

When you have converted a line to an arc, the original line is shown in grey. It will disappear next time you redraw the screen.

Click on [image] to undo a line to arc conversion.

•	NOTE: If you are making important changes to the vector image, don’t forget to save it frequently using Save As DXF or Save DXF in the File Menu! Alternatively, set Auto Save Vector in the File Menu.


Query Vector (Edit Vector Menu)

When you click on a vector after selecting Query Vector, the vector is highlighted. This function is particularly useful for seeing the extent of a polyline.


Make Polylines (Edit Vector Menu)

When you click on Make Polylines, joined individual lines on the vector image are converted into polylines.

To see the polylines that have been created, display vector colours using C on your keyboard, which toggles vector colours on and off. If vector colours are on, polylines are displayed in green and lines are displayed in red. Use Query Vector to highlight individual polylines.

Click on Un-Make Polylines in the Edit Vector Menu to convert polylines back into individual lines.


Un-Make Polylines (Edit Vector Menu)

When you click on Un-Make Polylines, polylines on the vector image are converted into individual lines. This is necessary for the following editing functions:

Split Line

Join Vectors

Line to Curve

Click on Make Polylines in the Edit Vector Menu to convert individual lines back into polylines.


Undo (Edit Vector Menu)

Undo undoes the following vector editing operations:

Line, Ortho Line, Rectangle, Circle, Arc, Freehand, Point, Move Grab Point, Move Grab Point Ortho, Split Line, Join Vectors, Curve to Line and Line to Curve.

If you use Area to delete an area of vectors, Undo will not undo the deletion.

Undo undoes your last action only.

See also Undo.


Type Menu

The Type Menu contains default vectorisation settings for vectorising different types of drawing like architectural, mechanical etc.

Vectorisation settings are the values of eight variables that control the conversion from raster to vector. These variables are:

Raster Line Width

Line Deviation Factor

Arc Deviation Factor

Vector Hline/Vline Snap

Vector Corner Snap

Vector Pass-Thro Snap

Orthogonality On

Poly On

For successful conversion, different drawings and applications need different vectorisation settings. For example, architectural floorplans tend to be made up of horizontal and vertical lines and Scan2CAD needs to try to keep these lines exactly horizontal and vertical. Maps on the other hand are made up of lines that go in all directions and Scan2CAD must not try to make these lines exactly horizontal and vertical.

To get the best possible conversion results the vectorisation settings must be optimal for the drawing or part of the drawing you are converting.

Scan2CAD is supplied with default vectorisation settings for converting the following types of drawings:

Architectural

Electrical

Mechanical

CNC Profiles

Map

Sketch

Outline  - outlines solid black areas like logos

User - your own defaults

Scanline  - converts solid black areas to parallel horizontal vectors

To choose a default setting, go to the Type Menu and select the drawing type you want. The Vectorisation Settings dialogue box will appear. Click on OK to accept the default settings or edit the settings and then click on OK. You can save edited settings by clicking on the Save button. Load previously saved settings by clicking on the Load button.

The default settings will work well for most drawings. However, to find the best settings for a particular drawing or part of a drawing, choose vectorisation settings and convert the drawing or drawing part by clicking on [image]. Once you have inspected the vectors that have been created, Undo the vectorisation by clicking on UnDo Vectorisation in the Run Menu. Repeat with different vectorisation settings until you are happy with the results.

You can change the default vectorisation settings. See Architectural, Electrical, Mechanical, CNC Profiles, Map, Sketch, User and Outline.

See also OCR Settings


Architectural (Type Menu)

Architectural sets the vectorisation settings to the default for architectural drawings.

The default architectural settings are as follows:

Raster Line Width 	14

Line Deviation Factor 	0

Arc Deviation Factor 	75

Vector Hline/Vline Snap 	2

Vector Corner Snap 	5

Vector Pass-Thro Snap 	5

Orthogonality On 	ticked

Poly On 	not ticked

OCR On 	ticked

You can change these settings to improve the conversion of a particular drawing or set of drawings. Any changes you make will be lost as soon as you click on another option in the Type Menu or exit Scan2CAD. To save your settings permanently, click on the Save button. You can save your settings under any name you choose but you must give them a .Set extension. Use the Load button to load previously saved settings.

To change the default architectural settings to give the best possible results on your own architectural drawings, change the values in the dialogue box, click on Save and save your settings as Arch.Set. Next time you select Architectural, your values will be loaded as default.


Electrical (Type Menu)

Electrical sets the vectorisation settings to the default for electrical drawings.

The default electrical settings are as follows:

Raster Line Width 	14

Line Deviation Factor 	0

Arc Deviation Factor 	75

Vector Hline/Vline Snap 	2

Vector Corner Snap 	5

Vector Pass-Thro Snap 	5

Orthogonality On 	ticked

Poly On 	not ticked

OCR On 	ticked

You may want to decrease the Raster Line Width setting so that solid circles on the drawing are not missed.

Any changes you make to the electrical settings will be lost as soon as you click on another option in the Type Menu or exit Scan2CAD. To save your settings permanently, click on the Save button. You can save your settings under any name you choose but you must give them a .Set extension. Use the Load button to load previously saved settings.

To change the default electrical settings to give the best possible results on your own electrical drawings, change the values in the dialogue box, click on Save and save your settings as Elec.Set. Next time you select Electrical, your values will be loaded as default.


Mechanical (Type Menu)

Mechanical sets the vectorisation settings to the default for mechanical drawings.

The default mechanical settings are as follows:

Raster Line Width 	14

Line Deviation Factor 	0

Arc Deviation Factor 	75

Vector Hline/Vline Snap 	2

Vector Corner Snap 	5

Vector Pass-Thro Snap 	5

Orthogonality On 	ticked

Poly On 	not ticked

OCR On 	ticked

You can change these settings to improve the conversion of a particular drawing or set of drawings. Any changes you make will be lost as soon as you click on another option in the Type Menu or exit Scan2CAD. To save your settings permanently, click on the Save button. You can save your settings under any name you choose but you must give them a .Set extension. Use the Load button to load previously saved settings.

To change the default mechanical settings to give the best possible results on your own mechanical drawings, change the values in the dialogue box, click on Save and save your settings as Mech.Set. Next time you select Mechanical, your values will be loaded as default.


CNC Profiles (Type Menu)

CNC Profiles sets the vectorisation settings to the default for profile drawings.

The default CNC profile settings are as follows:

Raster Line Width 	14

Line Deviation Factor 	0

Arc Deviation Factor 	75

Vector Hline/Vline Snap 	0

Vector Corner Snap 	0

Vector Pass-Thro Snap 	5

Orthogonality On 	not ticked

Poly On 	ticked

OCR On 	not ticked

You can change these settings to improve the conversion of a particular drawing or set of drawings. Any changes you make will be lost as soon as you click on another option in the Type Menu or exit Scan2CAD. To save your settings permanently, click on the Save button. You can save your settings under any name you choose but you must give them a .Set extension. Use the Load button to load previously saved settings.

To change the default CNC Profile settings to give the best possible results on your own profile drawings, change the values in the dialogue box, click on Save and save your settings as CNC.Set. Next time you select CNC Profiles, your values will be loaded as default.


Map (Type Menu)

Map sets the vectorisation settings to the default for maps and site plans.

The default map settings are as follows:

Raster Line Width 	14

Line Deviation Factor 	0

Arc Deviation Factor 	0

Vector Hline/Vline Snap 	0

Vector Corner Snap 	5

Vector Pass-Thro Snap 	5

Orthogonality On 	not ticked

Poly On 	ticked

OCR On 	not ticked

Note that if you use the default map settings, no arcs or circles will be recognised unless you enter a value for the Arc Deviation Factor.

Any changes you make to the map settings will be lost as soon as you click on another option in the Type Menu or exit Scan2CAD. To save your settings permanently, click on the Save button. You can save your settings under any name you choose but you must give them a .Set extension. Use the Load button to load previously saved settings.

To change the default map settings to give the best possible results on your own maps, change the values in the dialogue box, click on Save and save your settings as Map.Set. Next time you select Map, your values will be loaded as default.


Sketch (Type Menu)

Sketch sets the vectorisation settings to the default for sketches.

The default sketch settings are as follows:

Raster Line Width 	14

Line Deviation Factor 	1

Arc Deviation Factor 	0

Vector Hline/Vline Snap 	0

Vector Corner Snap 	0

Vector Pass-Thro Snap 	0

Orthogonality On 	not ticked

Poly On 	not ticked

OCR On 	not ticked

These settings trace exactly over the image. Because the Line Deviation Factor is set to 1, every blip and wobble in the raster image will be recognised. This means that the vector file that is produced will be made up of many short vectors.

You can change the sketch settings to improve the conversion of a particular drawing or set of drawings. Any changes you make will be lost as soon as you click on another option in the Type Menu or exit Scan2CAD. To save your settings permanently, click on the Save button. You can save your settings under any name you choose but you must give them a .Set extension. Use the Load button to load previously saved settings.

To change the default sketch settings to give the best possible results on your own sketches, change the values in the dialogue box, click on Save and save your settings as Sketch.Set. Next time you select Sketch, your values will be loaded as default.


Outline (Type Menu)

Outline sets the vectorisation settings to the default for outlining solid black areas such as logos.

The default outline  settings are as follows:

Raster Line Width 	1

Line Deviation Factor 	0

Arc Deviation Factor 	75

Vector Hline/Vline Snap 	0

Vector Corner Snap 	0

Vector Pass-Thro Snap 	0

Orthogonality On 	not ticked

Poly On 	ticked

OCR On 	not ticked

Raster Line Width has no effect in the outline settings. Outline will always follow the outline of a black area regardless of the Raster Line Width you set.

Note that if you use the default outline settings, no arcs or circles will be recognised unless you enter a value for the Arc Deviation Factor.

Any changes you make to the outline settings will be lost as soon as you click on another option in the Type Menu or exit Scan2CAD. To save your settings permanently, click on the Save button. You can save your settings under any name you choose but you must give them a .Set extension. Use the Load button to load previously saved settings.

To change the default outline settings to give the best possible results on your own drawings, change the values in the dialogue box, click on Save and save your settings as Outline.Set. Next time you select Outline, your values will be loaded as default.

•	NOTE: You can also convert solid black areas using the Scanline settings.


User (Type Menu)

This option is intended for your own default vectorisation settings.

Change the values in the dialogue box to what you want, click on Save and save your settings as User.Set. Next time you select User, your values will be loaded as default.

See:

Raster Line Width

Line Deviation Factor

Arc Deviation Factor

Vector Hline/Vline Snap

Vector Corner Snap

Vector Pass-Thro Snap

Orthogonality On

Poly On

OCR On


Scanline (Type Menu)

When Scanline is ticked, Scan2CAD creates an exact vector copy of the raster original. The vector image is made up of many closely spaced parallel horizontal lines.

Scanline is useful for artwork that contains solid black areas, like logos and illustrations. However, it creates very large DXF files.

•	NOTE: You can also convert solid black areas using the Outline settings.


OCR Menu

The functions in the OCR Menu allow you to select the optimum settings for OCR of text.

OCR Settings

OCR Char Size

OCR Build Strings


OCR Settings (OCR Menu)

The OCR Settings determine how Scan2CAD recognises text.

Character Size Limit

Scan2CAD will only recognise something as a character if it is smaller than the Character Size Limit, which is measured in pixels.

It is important to set the Character Size Limit correctly. If the Character Size Limit is too small, Scan2CAD will miss text that is larger than the Character Size Limit. If the Character Size Limit is too large, Scan2CAD may miss text even though it is smaller than the Character Size Limit. This is because it may think that the text is part of the drawing, not text.

To set the  Character Size Limit automatically, use OCR Char Size.

OCR Recognition Limit

The OCR Recognition Limit is a probability percentage.

For example, if you set the OCR Recognition Limit to 10, Scan2CAD will only recognise a character as a specific letter or number if it is more than 10% certain that the character is that letter or number. If it is less than 10% certain, the character will be recognised as a question mark (?).

Once Scan2CAD has recognised the text you can manually edit the question marks to the correct letter or number, either in your CAD program or in Scan2CAD (see Text).

You can also use Save Text File in the File Menu to save text that Scan2CAD has recognised as an ASCII text file. You can then edit the text in a text editor such as Windows Notepad or in a word processor.

Character Set

Scan2CAD recognises text by means of technology called neural networks. It is supplied with two neural network options, Standard and User.

The Standard network recognises text that has been written using standard fonts. These fonts are Arial, Sans Serif and Times New Roman. A sample file supplied with Scan2CAD, Text.Tif, shows the fonts that Scan2CAD has been trained to recognise. Scan2CAD may not recognise other fonts well. It may also fail to recognise Arial, Sans Serif and Times New Roman characters that are narrower or wider than standard.

If Scan2CAD cannot recognise the fonts on your drawings, you can train it to do so using the Scan2CAD Font Training Kit.

The User network recognises numbers and symbols only.

Normally, you should tick the Standard option. However if you have a drawing or an area of a drawing that contains numbers only, for example an area of dimensions, you should convert that drawing or drawing area with the User option ticked. Because the User option only recognises numbers, there is less likely to be confusion between similar numeric and non-numeric characters such as 6 and G.

Character Rotation

Text can become very confusing when viewed from different orientations. For example, a q is a b when looked at upside-down. Where the text you are recognising is all at the same orientation you should set that orientation in OCR Settings to ensure that Scan2CAD will only try to recognise text the right way up.

Where you have text at different orientations, you can set the orientation to Auto. Scan2CAD will then make a judgement about the orientation of each piece of text it tries to recognise but some text may be recognised the wrong way up. Scan2CAD is also more likely to recognise non-text parts of the drawing as text if orientation is set to Auto.

Where you have text at different orientations, it is a good idea to convert differently oriented text using different Character Rotation settings. Scan2CAD will only convert text that is displayed on the screen. This means you can zoom into text that is at 90 degrees and convert it using a 90 degree Character Rotation. You can then zoom into text that it at 0 degrees and convert it using a 0 degree Character Rotation. To make this process quicker, there are short cut keys for setting Character Rotation:

0 degrees	F1

90 degrees	F2

180 degrees	F3

270 degrees	F4

Display Mode

The normal Display Mode is Strings. When Display Mode is set to Strings, Scan2CAD recognises lines of text.

If you set Display Mode to Chars, text is recognised as individual characters rather than as lines of text. Numbers are displayed in green, upper-case letters in blue, lower-case letters in magenta and symbols in black. A number appears under each character. This number is the character’s probability percentage. For example if the character is an A, and the number under the character is 97, then Scan2CAD is 97% certain that the character is an A and not some other letter or number.

If you perform OCR with Display Mode set to Chars, you can later convert the individual characters to text strings by selecting OCR Build Strings. When you convert the characters to strings, Scan2CAD will convert all characters with a probability percentage less than the OCR Recognition Limit (see above) to question marks (?).

Regardless of whether you select Display Mode to Strings or Chars, you can toggle between displaying strings and individual characters by pressing the ? key after you have performed OCR.

See also

 Type Menu.


OCR Char Size  (OCR Menu)

OCR Char Size sets the Character Size Limit to the size of a character you click on plus a small percentage to allow for height variations.

To use OCR Char Size, zoom into a character that is representative of the text you want to convert.

Then select OCR Char Size from the OCR Menu. Immediately after selecting OCR Char Size, click on a black part of the character you have zoomed into. The character will be surrounded by a rectangle and the Character Size Limit will automatically be updated to the size of the character you just clicked on.

If you accidentally “miss” the character and click on a white space, Scan2CAD will continue to prompt you to click on a character until you successfully do so.


OCR Build Strings  (OCR Menu)

If you set Display Mode in OCR Settings to Chars, Scan2CAD recognises text as individual characters rather than as lines of text.

If you click on OCR Build Strings, these individual characters are joined together into lines of text.


Run Menu

The functions in the Run Menu do the conversion from raster to vector.

OCR 	Performs OCR on text in the raster image.

Vectorisation 	Converts the raster image to vectors, excluding text on which OCR has already been performed.

All 	Converts the raster image to vectors and performs OCR on the text.

Undo OCR 	Deletes the text that was recognised last time you ran OCR or All.

Undo Vectorisation 	Deletes the vectors that were recognised last time you ran Vectorisation or All.

Statistics 	Displays information about the vector file and the last conversion you did.


OCR  (Run Menu)

F6

OCR converts raster text to vector text. It does not convert non-text parts of the raster image.

For best results when converting a drawing that contains text you should use OCR to convert the text on the drawing first. Once you have achieved the best possible OCR conversion, use the Vectorisation option to vectorise the rest of the drawing.

The way that Scan2CAD recognises text is controlled by OCR Settings.

When you select OCR, Scan2CAD converts any raster text displayed on the screen to vector text. Because it only converts the text that is displayed on the screen, you can convert different text on the drawing using different OCR Settings.

To do this, choose the text you want to convert by zooming into it or by selecting it using Window Mode. Set OCR settings that suit the text you want to convert. Then convert the text using OCR. When it has been converted, choose another piece of text. Set OCR settings that suit the chosen text, then convert it using OCR etc.

You can Undo the last OCR you performed by selecting UnDo OCR from the Run Menu. To delete all vector text use Close Vector in the File Menu. This will also delete any vectors on your drawing unless you have previously saved them using Save As DXF in the File Menu.

Vector text is displayed in magenta unless you have set Display Mode in OCR Settings to Chars. You can add, edit or delete text using the Text function.

Characters that Scan2CAD is unsure about are displayed as question marks. The point at which Scan2CAD becomes unsure is the OCR Recognition Limit, which is set in OCR Settings. You can manually edit the question marks to the correct characters using the Text function in Scan2CAD, or you can edit them later in a text editor like Windows Notepad or in your CAD program.

You can save converted text to a text (ASCII) file using Save Text File in the File Menu. You can then load it into a text editor or word processor for correction and editing before importing it into your CAD program.

If OCR fails to recognise text or recognises text incorrectly, see Possible problems with OCR conversions.

See also:

Deleting vectors so you can try the conversion again

Vectorisation

All


Vectorisation (Run Menu)

F7

Vectorisation converts the raster image to lines, polylines, arcs and circles.

Vectorisation ignores areas of the raster image where text has already been found using OCR - these areas are “masked”. Any areas where you have deleted text that OCR has recognised, or where you have typed new text manually, are not masked and Scan2CAD will convert any raster parts of the image in these areas to lines, polylines, arcs and circles. The T key toggles masked area display on and off. Masked areas are shown as dashed boxes around text.

For best results when converting a drawing that contains text you should use OCR to convert the text on the drawing first. Once you have achieved the best possible OCR conversion, use Vectorisation to vectorise the rest of the drawing.

When you select Vectorisation, Scan2CAD converts the part of the raster image displayed on the screen to vectors. It uses the vectorisation settings currently ticked in the Type Menu. Because it only converts the image that is displayed on the screen, you can convert different parts of the raster image using different vectorisation settings.

To do this, choose the part of the image you want to vectorise by zooming into it or by selecting it using Window Mode. Set vectorisation settings that suit the part of the image you want to vectorise. Then vectorise the image part using Vectorisation. When it has been vectorised, choose another part of the image. Set vectorisation settings that suit the chosen part of the image, then vectorise it using Vectorisation, etc.

You can Undo the last Vectorisation you performed by selecting UnDo Vectorisation from the Run Menu. To delete all vectors, use Close Vector in  the File Menu. This will also delete any vector text you have recognised using OCR unless you have previously saved it using Save As DXF in the File Menu.

Vectors are displayed in red unless View Line Colours in the View Menu is ticked. In this case:

Lines are displayed in red.

Polylines are displayed in green.

Arcs are displayed in magenta.

Circles are displayed in blue.

C on your keyboard toggles View Line Colours on and off.

You can display grab points (vector end points, circle centre points, text origin points, arc mid points and circle 12 o’clock points) as squares. G toggles the display of vector end points, circle centre points, text origin points, arc mid points and circle 12 o’clock points on and off. P toggles the display of polyline end points on and off. Grab point size is controlled by Grab Point Size in the Edit Menu.

You can add, delete and edit vectors using the functions in the Edit Vector Menu.

If Vectorisation recognises vectors poorly, see Possible problems with drawing conversions.

See also:

Deleting vectors so you can try the conversion again

OCR

All


All (Run Menu)

F8

All converts raster text to vector text and converts the rest of the raster image to lines, arcs and polylines. It is a combination of OCR and Vectorisation.

•	NOTE: If you have the Outline or Scanline options ticked in the Type Menu, OCR will not be performed on the image when you run All.


Undo OCR (Run Menu)

[Ctrl]+F6

Undo OCR deletes the vector text that was recognised last time you used OCR or All.

Any edits you have made to this text since doing the OCR will be lost.


Undo Vectorisation (Run Menu)

[Ctrl]+F7

Undo Vectorisation deletes the vectors that were recognised last time you used Vectorisation or All.

Any edits you have made to these vectors since doing the vectorisation will be lost.


Statistics (Run Menu)

Statistics displays a box containing details about the vector file and the last conversion you did.

Vectors

This shows the number of vectors of different types in the vector file.

Time

This shows the time the last conversion took, whichever conversion option you used.

SnapShots

This is the number of “SnapShots” used during the last conversion.

In order to convert large raster files to vectors, Scan2CAD breaks the image down into several manageable parts called SnapShots. Each SnapShot comprises up to 8000 vectors. In large files vectors existing on either side of a SnapShot boundary may not be perfectly joined.

It is unlikely that a drawing will contain more than a few SnapShots unless you have specified vectorisation settings such as Sketch in the Type Menu, which will create many small vectors.


Batch Menu

The Batch Menu contains functions for setting up and running a batch file so you can convert multiple drawings at lunchtime or at some other time when your PC is not in use.

Batch Setup

Batch Run


Batch Setup (Batch Menu)

Batch Setup allows you to select up to six raster files for inclusion in a named batch file.

When the batch file is run, the raster files listed in it are automatically converted in the specified order and saved to specified vector files. Each raster file in the batch can have its own vectorisation settings.

The advantage of the batch file facility is that it allows you to convert  up to six large raster files, each of which may take a while to convert, at convenient times such as during lunch or overnight.

Creating a Batch File

The following is a step-by-step example of creating a batch file.

1.	Open the batch file

Select Batch Setup from the Batch Menu. The Open Batch File dialogue box appears. Specify a name for the batch file you are going to create, then click on OK.

2.	Select a raster file for inclusion in the batch file

The Batch Setup dialogue box appears.

Click on the Add Task button. The Open Raster File dialogue box appears. Select the first raster file you want to vectorise and click on OK.

The Vectorisation Settings dialogue box appears. Edit the vectorisation settings so that they are suitable for converting the raster file you have selected.

You can also load predefined settings by clicking on the Load button. You can load the default architectural, electrical, mechanical, cnc profile, map, sketch or outline settings by loading Arch.Set, Elec.Set, Mech.Set, CNC.Set, Map.Set or Outline.Set. Or you can load a .Set file you have previously defined yourself (see Architectural, Electrical, Mechanical, CNC Profiles, Map, Outline or User).

If you want Scan2CAD to perform OCR on the image as well as vectorise it, tick the OCR option (this option is ignored during normal on-screen conversion). Scan2CAD will use the currently set OCR Settings when performing OCR on the raster images in the batch file.

When you are satisfied with the vectorisation settings you have set, click on OK.

The Save As Vector File dialogue box appears. Type a name for the vector file that will be created from the raster file you have selected, then click on OK.

The Batch Setup dialogue box appears again. The raster file you have selected for conversion is listed in it together with the name of the vectorisation settings you are using and the name of the DXF file it will be converted to.

3.	Select more raster files to convert

Repeat Step 2 for up to five more raster files that you want to convert.

•	NOTE: You can add more than six files to a batch file if you add them manually using a text editor. See Using a Text Editor with Batch Files, below.

4.	Save the batch file

When you have added all the files you require to the Batch Setup dialogue box, click on the Save button. The batch file is created. You are returned to the main Scan2CAD screen.

Use Batch Run to convert the raster files listed in the batch file.

Using a Text Editor with Batch Files

At present, Scan2CAD's screen batch setup accepts a maximum of six raster files for batch file conversion. If you want to add more raster files to your batch file, or if you want to edit a batch file, you can do this using any text editor such as Windows Notepad.

•	NOTE: Scan2CAD batch files are plain ASCII text files with a .Rbt extension. If you load a Scan2CAD batch file into Notepad you will have to select All Files (*.*) in the Files of Type section at the bottom left of the Notepad Open dialogue box before you will be able to select the batch file for opening.

There is no limit on the number of raster files you can add to a batch file if you create or modify the batch file directly with a text editor.

Scan2CAD batch file format

C:\SCAN2CAD\FLRPLAN.TIF

C:\SCAN2CAD\FLRPLAN.DXF

arch.set

14

0

75

2

5

5

1

1

0

EOF

Each raster file in a Scan2CAD batch file is represented by a block of twelve lines. The first two lines of each block list the raster file to be converted and the name of the vector file it is to be converted to.

The third line lists the name of the .Set file containing the vectorisation settings to be used for the conversion.

The final six lines are the vectorisation settings:

Raster Line Width

Line Deviation Factor

Arc Deviation Factor

Vector Hline/Vline Snap

Vector Corner Snap

Vector Pass-Thro Snap

Orthogonality On

OCR On

Poly On

Orthogonality On, OCR On and Poly On are set to 1 if they are ticked, and to 0 if they are not ticked.

The last line of the batch file must read EOF.


Batch Run (Batch Menu)

Batch Run runs a batch file created using Batch Setup. The advantage of running a batch file is that it allows you to convert drawings at lunchtime or at some other time when your PC is not in use.

When you select Batch Run, the Open Batch File dialogue box appears. Select the batch file you want to run and click on OK.

Scan2CAD will convert the raster files listed in the batch file one by one and store them in a vector DXF format in the files you have specified. It will use the vectorisation settings specified in the batch file. If you have specified that you want OCR on any of the raster files to be converted, Scan2CAD will use the OCR settings that are currently set in the OCR Settings dialogue box.

Scan2CAD performs the conversion on screen. You can see it converting one file after another. The length of time the conversions take is dependent on the speed of your PC and the number and size of the drawings being converted.


Icons

File Icon

Open Raster File.

View Icons

Window Mode - changes the cursor to an arrow that you can use to select an area of the image to zoom into or to vectorise.

View Raster File - displays the raster file only. Redraws the screen. Zooms into an area you have selected using Window Mode.

View Vector File - displays the vector file only. Redraws the screen. Zooms into an area you have selected using Window Mode.

View Both Files - displays both the raster and the vector file. Redraws the screen. Zooms into an area you have selected using Window Mode.

Zoom In - zooms in around the screen centre.

Zoom Out - zooms out around the screen centre.

Edit Icons

Edit Raster. If you select this icon, the edit icons operate on the raster file so that you can draw onto the raster image or erase parts of it. For example, you might want to improve a badly scanned line by drawing over it, or erase a dirty mark on the image. See Raster Draw Mode and Raster Erase Mode.

Edit Vector. If you select this icon, the edit icons operate on the vector file so that you can draw, erase or edit vectors. See Vector Draw Mode and Vector Erase Mode.

Draw. If you select this icon, the edit icons draw onto the raster or vector file depending on whether the edit raster icon or the edit vector icon is currently selected. See Raster Draw Mode and Vector Draw Mode.

Erase. If you select this icon, the edit icons allow you to erase parts of the raster or vector file depending on whether the edit raster icon or the edit vector icon is currently selected. See Raster Erase Mode and Vector Erase Mode.

Undo - undoes the last edit you made to the raster or vector image. See Undo (Edit Raster Menu) and Undo (Edit Vector Menu).

Line.

  	When these three icons are selected, line draws raster lines.

  	When these three icons are selected, line erases raster lines.

  	When these three icons are selected, line draws vector lines.

  	When these three icons are selected, line erases any vector.

Ortho Line.

  	When these three icons are selected, ortho line draws orthogonal raster lines.

  	When these three icons are selected, ortho line erases orthogonal raster lines.

  	When these three icons are selected, ortho line draws orthogonal vector lines.

  	When these three icons are selected, ortho line erases any vector.

Rectangle.

  	When these three icons are selected, rectangle draws raster rectangles.

  	When these three icons are selected, rectangle erases raster rectangles.

  	When these three icons are selected, rectangle draws vector rectangles.

  	When these three icons are selected, rectangle erases any vector.

Circle.

  	When these three icons are selected, circle draws raster circles.

  	When these three icons are selected, circle erases raster circles.

  	When these three icons are selected, circle draws vector circles.

  	When these three icons are selected, circle erases any vector.

Arc.

  	When these three icons are selected, arc draws raster arcs.

  	When these three icons are selected, arc erases raster arcs.

  	When these three icons are selected, arc draws vector arcs.

  	When these three icons are selected, arc erases any vector.

Freehand.

  	When these three icons are selected, freehand draws raster sketches.

  	When these three icons are selected, freehand erases raster sketches.

  	When these three icons are selected, freehand draws vector sketches.

  	When these three icons are selected, freehand erases any vector.

Point.

  	When these three icons are selected, point draws raster points.

  	When these three icons are selected, point erases raster points.

  	When these three icons are selected, point draws vector points.

  	When these three icons are selected, point erases any vector.

Area.

  	When these three icons are selected, area draws a solid black raster area.

  	When these three icons are selected, area erases a raster area. This is very useful for erasing dirty areas of the raster image.

  	When these three icons are selected, area erases all the vectors within an area.

Text.

  	When these three icons are selected, text draws or edits vector text.

  	When these three icons are selected, text erases any vector.

SnapTidy Icons

Move Grab Point - moves a grab point (vector end point, circle centre point, text origin point, arc mid point or circle 12 o’clock point).

Move Grab Point Ortho - moves a grab point orthogonally.

Split Line - splits a vector line.

Join Vectors - merges two vectors.

Curve to Line - converts a vector arc to a vector line.

Line to Curve - converts a vector line to a vector arc.

Query Vector - highlights a vector.

Run Icons

OCR - performs OCR on text in the raster image.

Vectorisation - converts the raster image to vectors, excluding text on which OCR has already been performed.

All - converts the raster image to vectors and performs OCR on the text.


Short-cut keys

View

W	Window Mode - changes the cursor to an arrow that you can use to select an area of the image to zoom into or to vectorise.

R	View Raster File - displays the raster file only. Redraws the screen. Zooms into an area you have selected using Window Mode.

V	View Vector File - displays the vector file only. Redraws the screen. Zooms into an area you have selected using Window Mode.

B	View Both Files - displays both the raster and the vector file. Redraws the screen. Zooms into an area you have selected using Window Mode.

C	Toggles View Line Colours on and off.

G	Toggles View Grab Points on and off (vector end points, circle centre points, text origin points, arc mid points and circle 12 o’clock points).

P	Toggles View Grab Points on and off (polyline end points).

T	Toggles View Text Extents on and off.

Zoom

Home	Zoom Extents - zooms out so you can see the whole image.

*	Redraw - redraws the screen. Zooms into an area you have selected using Window Mode.

F or

/ on the numeric keypad	Fill. When you are zoomed in, fill increases the amount of the image that is displayed to fill the screen. Subsequent uses of Fill shrink what is displayed slightly so you can see more of the image on the screen.

M	Magnifies around the current cursor position.

+ on the numeric keypad 	Zoom In - magnifies around the screen centre.

D	Demagnifies around the current cursor position.

- on the numeric keypad 	Zoom Out - demagnifies around the screen centre.

Delete	Zoom Previous - steps back through the last ten zooms you have used, one at a time.

Pan

Down Arrow	Pans down incrementally.

Up Arrow 	Pans up incrementally.

Left Arrow	Pans left incrementally.

Right Arrow	Pans right incrementally.

[Ctrl]+Down Arrow or

Page Down	Pans down by a page.

[Ctrl]+Up Arrow or

Page Up	Pans up by a page.

[Ctrl]+Left Arrow	Pans left by a page.

[Ctrl]+Right Arrow	Pans right by a page.

Z	Pans the part of the image at the current cursor position to the screen centre.

Edit Raster

[Ctrl]+L	Rotate Image by Line - deskews raster image.

Edit Vector

The numbers below are the numbers above QWERTY on your main keyboard, not the numbers on the numeric keypad.

0	Sets Grab Snap Distance to 0 pixels.

1	Sets Grab Snap Distance to 1 pixels.

2	Sets Grab Snap Distance to 2 pixels.

4	Sets Grab Snap Distance to 4 pixels.

8	Sets Grab Snap Distance to 8 pixels.

A	Toggles Attach Grab Points so that one or both vectors will be moved when you move a common grab point.

OCR

F1	Sets Character Rotation in OCR Settings to 0 degrees.

F2       	Sets Character Rotation in OCR Settings to 90 degrees.

F3       	Sets Character Rotation in OCR Settings to 180 degrees.

F4     	Sets Character Rotation in OCR Settings to 270 degrees.

?       	Toggles display between individual characters and text strings. See Display Mode.

Run

F6	OCR - performs OCR on text in the raster image.

F7	Vectorisation - converts the raster image to vectors, excluding text on which OCR has already been performed.

F8	All - converts the raster image to vectors and performs OCR on the text.

[Ctrl]+F6	UnDo OCR - deletes the vector text that was recognised last time you used OCR or All.

[Ctrl]+F7	UnDo Vectorisation - deletes the vectors that were recognised last time you used Vectorisation or All.


Pixels

A raster file is made up of little squares called pixels as shown in the diagram below. Lines and arcs in a raster file are represented by filling in the appropriate pixels.


Polylines

Polylines are lines that are made up of lots of shorter lines that have been joined together to form one entity:

Viewing polylines

C on your keyboard toggles vector colours on and off. If vector colours are on, polylines are  displayed in green.

P on your keyboard toggles polyline end point display on and off. Polyline end points are displayed as filled green squares. The size of these squares is controlled by Grab Point Size in the Edit Menu.

If you click on [image] then on a vector, the vector will be highlighted. This is a useful way of viewing the extent of a polyline.

Splitting polylines into individual lines

The Split Line, Join Vectors and Line to Curve functions don’t work on polylines. Before you can use these functions on a line that is part of a polyline, you need to split the polyline.

If you click on Un-Make Polylines in the Edit Vector Menu, all the polylines on the vector image are split into individual lines. Individual lines are displayed in red when vector colours are turned on.

Joining individual lines together to form polylines

To make polylines from individual lines, click on Make Polylines in the Edit Vector Menu. Scan2CAD will join as many individual lines in the vector image as it can together into polylines.


Preparing a raster file for conversion

Raster files are normally created by scanning a paper-based drawing into your computer using a scanner.

The paper-based drawing

The paper-based drawing that you scan in needs to be as high quality as possible. Any dirty marks will be scanned in along with the drawing, and any faint or smudged areas will not scan well.

Scan2CAD will convert any size of drawing. Drawing size is only limited by the size of your scanner.

The scanner

You can use any scanner to create a raster file for use with Scan2CAD so long as the software supplied with the scanner can save a raster file in one of the following formats:

•	IMG

•	PCX

•	BMP (uncompressed only)

•	TIFF (uncompressed, packbits, CCITT fax group 3 or CCITT fax group 4 compressed formats)

Your scanner software also needs to be able to save the raster file as a mono file, i.e. black and white only. Scan2CAD does not read colour or greyscale images.  If it’s not obvious how to save a mono file using your scanner software, look for options like “monochrome”, “line art”, “faster scan speed” or “black and white drawing”.

You can also use image editing programs like Paintshop Pro to convert a raster image to mono and to save it in a suitable format.

If you do not have a scanner, there are many companies who will scan your drawing or drawings for a small fee.

Scanner resolution

When scanning your drawing, you need to strike a balance between scanner resolution that is too low and scanner resolution that is too high. If the resolution is too low, there will not be enough information in the raster image and Scan2CAD will not be able to convert the image well. If the resolution is too high, the scanner will pick up every little blip and wobble in the drawing. Scan2CAD will convert all this detail, intentional or unintentional. Further, the raster image will be much larger than it needs to be, meaning that the image will take longer to convert.

The “right” resolution depends on the individual drawing but 200 to 300 dpi is right for most drawings.

The default settings in Scan2CAD’s Type Menu are intended for scans with a 200 to 300 dpi resolution. If you scan at a high resolution you may have to increase the Vector Hline/Vline Snap, Vector Corner Snap and Vector Pass-Thro Snap which are measured in pixels.

Raster file size

Scan2CAD will convert any size of raster file although in practice the maximum file size that it will handle is determined by your PC’s system resources - for example the amount of physical and virtual RAM it has.

We recommend that you try to keep your raster files small to save disk space and processing time. You can do this by not scanning at a high resolution. 200 to 300 dpi is optimal for most images and there is no point creating an unnecessarily large file by scanning with an unnecessarily high resolution.

If you are using Windows ‘95 or ‘98 and your image is larger than 32,000 pixels in either width or height, Scan2CAD will automatically split it into smaller more manageable “tiles”. These tiles can be converted separately and then joined back together again after conversion. You can join the tiles back together using Merge Vector in Scan2CAD, or you can join them back together in your CAD program. Scan2CAD does this due to a Windows-imposed limit on raster image size in Windows ‘95 and ‘98. In Windows NT there is effectively no limit on raster image size.

Raster file quality

To get a good quality raster file, ensure the following:

•	Make sure the paper-based drawing that you scan in is as clean and crisp as possible. If it contains dirty marks, these will be scanned in together with the drawing. Smudged or faint lines will not scan well and this will make it harder for Scan2CAD to produce a good conversion.

The scanning software supplied with your scanner may be able to tidy up grey backgrounds, dirty marks and speckles. Scan2CAD also includes clean-up functions in its Edit Raster Menu.

•	Take care not to scan the drawing skew. The raster file that is created should have lines that were horizontal and vertical on the paper-based drawing as close to horizontal and vertical as possible.

If you do scan your drawing in slightly skew, you can deskew it using Scan2CAD’s Rotate Image by Degrees or Rotate Image by Line commands. Just a fraction of a degree is usually enough to deskew a drawing.

Your scanner will only create a raster file as good as the paper-based drawing and the care with which it is scanned. If the quality of the raster file is poor, Scan2CAD will not be able to convert it well. “Garbage In, Garbage Out”!


Raster Line Width

The Raster Line Width is set in the Type Menu. It determines whether Scan2CAD recognises outlines, centre lines or both.

When Scan2CAD vectorises a line that is thinner than the Raster Line Width, the vector it creates follows the centre of the line. When Scan2CAD vectorises a line that is thicker than the Raster Line Width, the vector it creates follows the outsides of the line. The diagram below shows the effect of Raster Line Width.

To recognise outlines only, set Raster Line Width to 1.

•	NOTE: If you want to recognise outlines, see also Outline.

To recognise both outlines and centre lines, set Raster Line Width to the thickness, in pixels, of most of the lines on the drawing. This is typically a figure between 4 and 9.

To recognise centre lines only, set Raster Line Width to a value greater than the thickness, in pixels, of the thickest line on the drawing. If you set a high Raster Line Width be aware that you may lose drawing detail. This is illustrated in the diagram above where the Raster Line Width setting of 25 has caused the “blob” in the raster image to be lost. Also, the higher the Raster Line Width the longer the image will take to convert.

•	NOTE: To determine the thickness of a line in pixels, zoom into it. Click on [image] and then on [image] and then on an edit icon such as [image]. The cursor will change shape and will have one or two boxes around it. The box (or the smaller box if there are two boxes) is the size of one pixel. Slowly move the cursor over the line. The box will “jump” from one pixel to the next. Count the number of pixels.


Line Deviation Factor

The Line Deviation Factor is set in the Type Menu. It determines the amount of detail that Scan2CAD recognises. It is the number of pixels that Scan2CAD “looks ahead” when it is tracking an image.

If you set the Line Deviation Factor to 0, Scan2CAD judges the Line Deviation Factor for itself as it vectorises the image. It uses different Line Deviation Factors on different parts of the image to try to get the best possible vectorisation results.

There is no need to set the Line Deviation Factor to any value other than 0 unless Scan2CAD is missing small details you would like to keep or unless you would like the vectorised image to look smoother. In this case you may want to try setting the Line Deviation Factor manually.

If you set the Line Deviation Factor to 1, Scan2CAD “looks ahead” to the pixel next to the one it is currently on and moves there. Because it “stops to look” at every pixel, it can detect every slight wiggle or deviation in a line.

As you increase the Line Deviation Factor, some fine detail may be lost and the vector image will contain fewer lines. Increasing the Line Deviation Factor stops having an effect when the Line Deviation Factor value would cause the essential shape of the raster image to be lost.


Arc Deviation Factor

The Arc Deviation Factor is set in the Type Menu. It determines whether Scan2CAD recognises arcs and circles on the image. It also determines whether the vector arcs that Scan2CAD recognises must lie completely on top of the raster arcs or whether parts of the vector arcs can lie off the raster arcs, on white pixels.

For example, in the diagram below the left hand arc  is positioned entirely over the raster image. The right hand arc does not fit entirely over the raster image - it passes over some white pixels.

The Arc Deviation Factor is the percentage of an arc that must pass over black pixels. The lower the Arc Deviation Factor, the more arcs Scan2CAD is likely to recognise. However, arcs it recognises may not be an accurate reflection of the arcs on the raster image.

An Arc Deviation Factor of 0 means that Scan2CAD will not recognise any arcs or circles on the image - all arcs and circles will be recognised as lines.


Vector Hline/Vline Snap

Vector Hline/Vline Snap is set in the Type Menu. Its effect is best seen in the diagrams below.

Adjacent horizontal lines that fall within the Vector Hline/Vline Snap distance are joined to form one single horizontal line.

Adjacent vertical lines that fall within the Vector Hline/Vline Snap distance are joined to form one single vertical line.

You should not set Vector Hline/Vline Snap too high or horizontal and vertical lines that you want to keep separate may be lost. Suitable values are 1 or 2 pixels.


Vector Corner Snap

Vector Corner Snap is set in the Type Menu. It defines a search distance, measured in pixels, around the ends of vector lines. If another line, or the end of another line, is discovered within the search distance and the two lines potentially intersect, they are joined.

In the left hand diagram below, the Vector Corner Snap search distance is represented by circles. In the right hand diagram, lines falling within the search distance have been snapped together. Note that at the arrowed corner, the short diagonal line joining the two end points has been deleted and that the end points of the two main lines have been snapped together to make a corner. Effectively the corner has been “sharpened”.

A Vector Corner Snap of between 2 and 5 is optimal for most images. If you set the Vector Corner Snap too high, lines will be incorrectly connected.


Vector Pass-Thro Snap

Vector Pass-Thro Snap is set in the Type Menu.

Where two lines cross each other untidily as in the raster image below, Scan2CAD inserts a short joining vector. Scan2CAD deletes all joining vectors shorter than the Vector Pass-Thro Snap, allowing it to create a tidy line crossing.

The Vector Pass-Thro Snap is measured in pixels. A typical value is 5.


Orthogonality On

Orthogonality On is set in the Type Menu. It restores lines that deviate very slightly from true horizontal or vertical to 0° and 90°.

Tick Orthogonality On if you are vectorising a drawing with a large number of horizontal and vertical lines such as an architectural floorplan.

If Orthogonality On is not ticked, lines that deviate very slightly from the horizontal or vertical will be left as they are. Don’t tick Orthogonality On if you are vectorising a drawing like a map.


Poly On

Poly On is set in the Type Menu. If it is ticked, Scan2CAD will join individual lines together to form polylines where it can during vectorisation.

If you are going to edit vectors in Scan2CAD it is best not to tick Poly On as the vector editing functions Split Line, Join Vectors, Curve to Line and Line to Curve do not work on polylines.

If you have not ticked Poly On, you can create polylines after vectorisation by clicking on Make Polylines in the Edit Vector Menu. Similarly if you have ticked Poly On you can split the Polylines into individual lines by clicking on Un-Make Polylines in the Edit Vector Menu.


OCR On

OCR On is set in the Type Menu.

This option is only relevant if you are doing batch conversions. When you are converting normally on the screen the OCR On option is ignored and whether OCR is performed or not is determined by the conversion option you choose - OCR, Vectorisation or All.

If OCR On is ticked, Scan2CAD will perform OCR during a batch run, as well as recognising vectors (the equivalent to the All conversion option). If OCR is not ticked, Scan2CAD will recognise vectors only (the equivalent to the Vectorisation conversion option).


Zooming

Main zoom short cut keys and icons

Short-cut key/icon	Action

Home	Zoom Extents - zooms out so you can see the whole image.

M	Magnifies around the current cursor position.

+ on the numeric keypad 	Zoom In - magnifies around the screen centre.

D	Demagnifies around the current cursor position.

- on the numeric keypad 	Zoom Out - demagnifies around the screen centre.

Delete	Zoom Previous - steps back through the last ten zooms you have used, one at a time.

Selecting an area to zoom into

1.	If the cursor is not in Window Mode ( [image] ) click on [image], press the W key or choose Window Mode from the View Menu.

2.	Drag a rectangle around the area you want to zoom into (drag top left to bottom right). The area you have selected will be marked by a dotted rectangle. If you are not satisfied with your selection simply drag another rectangle.

3.	To zoom into the selected area, press:

 * on your numeric keypad. What is displayed in the selected area (raster, vector or both images) depends on which icon ( [image], [image] or [image]) is currently depressed.

Or:	 or R on your keyboard to zoom in and view the raster file only.

Or:	 or V on your keyboard to zoom in and view the vector file only.

Or:	 or B on your keyboard to zoom in and view both files.

If the icon you want to use ( [image], [image] or [image])  is already depressed you can still click on it to zoom into the view you want.

When you select an area to zoom into, Scan2CAD zooms into the exact area you have selected. No additional part of the image is displayed. You can increase the amount of image that is displayed to fill the screen using Fill.

Note

If you vectorise the raster file when you are zoomed in, only the displayed part of the image will be vectorised. If you use Outline Image, Speckle Removal, Hole Removal, Curve Thin Image, Ortho Thin Image or Thicken Image from the Edit Raster Menu only the displayed area will be affected.

See Also

Panning

View Menu


Panning

You can pan around the screen using the scroll bars or the following keyboard short-cuts:

Short-cut key/icon	Action

Down Arrow	Pans down incrementally.

Up Arrow 	Pans up incrementally.

Left Arrow	Pans left incrementally.

Right Arrow	Pans right incrementally.

[Ctrl]+Down Arrow or

Page Down	Pans down by a page.

[Ctrl]+Up Arrow or

Page Up	Pans up by a page.

[Ctrl]+Left Arrow	Pans left by a page.

[Ctrl]+Right Arrow	Pans right by a page.

Z	Pans the part of the image at the current cursor position to the screen centre.


Redrawing the screen

To redraw the screen so that grey lines representing the old positions of edited or deleted vectors disappear, press:

* on your numeric keypad. What is displayed in the selected area (raster, vector or both images) depends on which icon ( [image], [image] or [image]) is currently depressed.

Or:	 or R on your keyboard to redraw and view the raster file only.

Or:	 or V on your keyboard to redraw and view the vector file only.

Or:	 or B on your keyboard to redraw and view both files.

If the icon you want to use ( [image], [image] or [image])  is already depressed you can still click on it to redraw the view you want.


Possible problems with reading a raster image into Scan2CAD

If you have problems reading a scanned raster image into Scan2CAD, check the following:

What format is your file in?

Scan2CAD supports the following file types:

•	IMG

•	PCX

•	BMP (uncompressed only)

•	TIFF (uncompressed, packbits, CCITT fax group 3 or CCITT fax group 4 compressed formats)

If your raster file is of an incompatible type, scan it again and save it in one of the formats listed above. Your scanner software will almost certainly save in one of these formats. Alternatively, convert the file to a supported format using an image editing program like Paintshop Pro.

Is your file a TIFF file?

If your file is a TIFF file, you may get warning or error messages when you read it in. Click on OK to pass these messages. Your file will probably load successfully in spite of them.

If you do not want these messages to appear in future, click on Raster Tiff Warnings in the File Menu so that it becomes unticked.

Is your file mono?

Make sure your raster file is mono, i.e. black and white only. Scan2CAD will not read colour or greyscale images. Even if your file looks mono, it may still be colour or greyscale.

A really useful program for checking whether an image is mono or colour is Paintshop Pro. If you have a copy, load your image into it and go to the Colors Menu. Choose Decrease Color Depth. If all the options are greyed out, then the image is a mono image. Otherwise, it’s a colour or greyscale image.

If your image is colour or greyscale, you have two options:

•	Scan the drawing in again, this time making sure you save it as a mono file. If it’s not obvious how to save a mono image using your scanner software, look for options like “monochrome”, “line art”, “faster scan speed” or “black and white drawing”.

•	Convert the image to mono in an image editing program such as Paintshop Pro. To convert a colour or greyscale image to mono in Paintshop Pro, go to the Colors Menu and choose Decrease Color Depth. Then click on 2 Colors. Click on OK to accept Paintshop Pro’s defaults in the dialogue box. Then save the file. It will now be mono.

Did you create your raster image in Adobe® Photoshop®?

To create a Scan2CAD compatible raster image in Adobe Photoshop, you first need to make sure your image is mono, not colour or greyscale. Photoshop calls mono images “bitmap” images. To convert an image to mono in Photoshop go to Photoshop’s Image Menu, then to Mode, then to Bitmap.

Sometimes this can cause the image to convert to a mass of black speckles. To get around this you can adjust the level of black in the image before converting it to mono. To do this, go to Photoshop’s Image Menu, then to Adjust, then to Curves. If you convert the image to mono after adjusting the level of black, you may get much better results.

Once your file is mono, you need to save it in a format acceptable to Scan2CAD. Adobe products use a TIFF compression format called LZW, which Scan2CAD doesn’t support. To get around this, you need to save your image in one of the following formats:

•	As an uncompressed TIFF file. Go to Photoshop’s Save As command and choose TIFF as the file type. In the TIFF options dialogue box that appears choose IBM PC byte order and untick the LZW option. Scan2CAD will read the uncompressed TIFF file that Photoshop creates although it will give you a TIFF warning message on opening. Click on OK to pass the warning message.

•	As a BMP file. Go to Photoshop’s Save As command and choose BMP as the file type. In Photoshop’s BMP Options dialogue box you need to choose the Windows and 1-bit options. Scan2CAD will read a Photoshop BMP file but it will be reversed out - i.e. black areas will be white and vice versa. Once the BMP file is in Scan2CAD, go to Scan2CAD’s Edit Raster Menu and choose Negative Image. This will reverse the image back so that the colours are correct.

•	As a PCX file. Like Photoshop BMP files, Photoshop PCX files arrive in Scan2CAD reversed out. Use Scan2CAD’s Negative Image command to correct this.

How large is your file?

Scan2CAD will convert any size of raster file although in practice the maximum file size that it will handle is determined by your PC’s system resources - for example the amount of physical and virtual RAM it has.

We recommend that you try to keep your raster files small to save disk space and processing time. You can do this by not scanning at a high resolution. 200 to 300 dpi is optimal for most images and there is no point creating an unnecessarily large file by scanning with an unnecessarily high resolution.

If you are using Windows ‘95 or ‘98 and your image is larger than 32,000 pixels in either width or height, Scan2CAD will automatically split it into smaller more manageable “tiles”. These tiles can be converted separately and then joined back together again after conversion. You can join the tiles back together using Merge Vector in Scan2CAD, or you can join them back together in your CAD program. Scan2CAD does this due to a Windows-imposed limit on raster image size in Windows ‘95 and ‘98. In Windows NT there is effectively no limit on raster image size.

Where is your file stored?

Scan2CAD cannot convert raster files if they are stored on a floppy disk, on a CD or on part of a network you don’t have write access to.

Make sure your raster file is stored on your hard drive and make sure you have some free hard disk space, especially if you are getting error messages about writing files or allocating memory.

Error messages about temp files, creating files, writing files or allocating image memory

If you get any error messages about temp files, creating files, writing files or allocating image memory check the following:

•	Is your raster file stored on media that Scan2CAD can’t write to, like a CD or part of a network that you don’t have write access to? If so, copy the raster file to your hard drive and try again.

•	Check that you have free hard disk space on your PC.


Possible problems with OCR conversions

If OCR fails to recognise text or recognises text incorrectly, check the following.

Raster image quality

If text has been missed, zoom into the raster image and look at the text. What is the quality like? Do the letters run into each other as in the example below? If the quality of the raster text is poor, Scan2CAD will not be able to recognise it. “Garbage In, Garbage Out”!

If the quality of the raster text is poor, the only remedy is to start off with a better quality raster image. If this is not possible, you can either add the text manually in Scan2CAD (see Text) or later in your CAD program. You may want to erase areas of very poor quality raster text (see Area) so that these areas are not vectorised to lines and arcs.

Text size

Scan2CAD is unlikely to recognise text that is smaller than five pixels in size, or even text that is slightly larger than this where letters are complex. This is because where text is very small there are simply not enough pixels in each letter to adequately represent the letter so that it can be recognised.

Character Size Limit

It is important to set the Character Size Limit in OCR Settings correctly. If the Character Size Limit is too small, Scan2CAD will miss text that is larger than the Character Size Limit. If the Character Size Limit is too large, Scan2CAD may miss text even though it is smaller than the Character Size Limit. This is because it may think that the text is part of the drawing, not text.

Use OCR Char Size in the OCR Menu to set the Character Size Limit automatically.

To use OCR Char Size, zoom into a character that is representative of the text you want to convert. Then select OCR Char Size from the OCR Menu. Immediately after selecting OCR Char Size, click on the character you have zoomed into. The character will be surrounded by a rectangle and the Character Size Limit will automatically be updated to the size of the character you have just clicked on.

Character Rotation

Text can become very confusing when viewed from different orientations. For example, a q is a b when looked at upside-down. Where the text you are recognising is all at the same orientation you should set that orientation in OCR Settings to ensure that Scan2CAD will only try to recognise text the right way up.

Where you have text at different orientations, you can set the orientation to Auto. Scan2CAD will then make a judgement about the orientation of each piece of text it tries to recognise but some text may be recognised the wrong way up. Scan2CAD is also more likely to recognise non-text parts of the drawing as text if orientation is set to Auto.

Where you have text at different orientations, it is a good idea to convert differently oriented text using different orientation settings. Scan2CAD will only convert text that is displayed on the screen. This means you can zoom into text that is at 90 degrees and convert it using a 90 degree orientation setting. You can then zoom into text that it at 0 degrees and convert it using a 0 degree orientation setting. To make this process quicker, there are short cut keys for setting orientation:

0 degrees	F1

90 degrees	F2

180 degrees	F3

270 degrees	F4

Display Mode

If the text that has been recognised is higgeldy-piggeldy and displayed in different colours, this is because Display Mode in OCR Settings is set to Chars. Click on Build Strings in the OCR Menu to join the individual characters together to make text strings.

Character Set - fonts

By default, Scan2CAD can only recognise text that is written in standard fonts. These fonts are Arial, Sans Serif and Times New Roman. A sample file supplied with Scan2CAD, Text.Tif, shows the fonts that Scan2CAD has been trained to recognise. Scan2CAD may not recognise other fonts well. It may also fail to recognise Arial, Sans Serif and Times New Roman characters that are narrower or wider than standard.

If Scan2CAD cannot recognise the fonts on your drawings, you can train it to do so using the Scan2CAD Font Training Kit.

Character Set - letters and numbers

Scan2CAD recognises text by means of technology called neural networks. It is supplied with two neural network options, Standard and User. You can choose between Standard and User in OCR Settings.

Standard recognises text that is written in standard fonts. It recognises both letters and numbers. User recognises numbers only.

If you have a drawing or an area of a drawing that contains numbers only, for example an area of dimensions, you should convert that drawing or drawing area with the User option ticked. Because the User option only recognises numbers, there is less likely to be confusion between similar numeric and non-numeric characters such as 6 and G.

Don’t forget to tick Standard again after you have finished recognising numbers or Scan2CAD will convert all your text to numbers!

Text position

If text is written over lines and arcs, Scan2CAD probably won’t be able to recognise it.

In this example, Scan2CAD won’t recognise the letter C. You can add the C after running OCR, by editing the POR  H text, using the Text function.

Vectorisation settings

If you converted your drawing using All and no text has been recognised, go to the Type Menu and see which option is ticked.

If Outline or Scanline are ticked, Scan2CAD won’t recognise text when you convert your drawing using All. To convert your drawing you need to use OCR first, then Vectorisation.

Try converting the drawing in parts

When you run OCR, Scan2CAD only converts the part of the image that is displayed on the screen. This means that you can convert different areas of text separately using different OCR Settings for areas of different sized text, text at different orientations, letters, numbers etc. This will give you better OCR results.

If you only convert areas of text and not the whole drawing, Scan2CAD is also less likely to recognise text where none exists.

Error messages about temp files, creating files, writing files or allocating image memory

If you get any error messages about temp files, creating files, writing files or allocating image memory during a conversion, check the following:

•	Is your raster file stored on media that Scan2CAD can’t write to, like a CD or part of a network that you don’t have write access to? If so, copy the raster file to your hard drive and try again.

•	Check that you have free hard disk space on your PC.

See also

Deleting vectors so you can try the conversion again.

Possible problems with drawing conversions.


Possible problems with drawing conversions

If Vectorisation recognises vectors poorly, check the following.

Raster image quality

The most common reason for poor quality vectorisation results is a poor quality scanned raster image. If you get a poor quality conversion, zoom into the raster image and look at it. Are the raster lines clean and continuous? Or are they broken up? Do they contain white holes? If the lines in the original raster image are broken up, Scan2CAD cannot convert them to smooth, continuous lines. “Garbage In, Garbage Out”!

If the quality of the raster image is poor, try scanning the original drawing again. If this doesn’t give you a better quality raster image you can sometimes go some way to getting better results using Scan2CAD's raster editing tools. You can draw over individual badly-scanned raster lines or arcs using Raster Draw Mode. Use Speckle Removal to remove black speckles from white areas. Use Hole Removal or Thicken Image to fill white holes in black areas. If the lines are very thin, thicken them using Thicken Image.

Raster image rotation

If you have a drawing with lots of horizontal and vertical lines on it, you will get much better vectorisation results if you scan the drawing in straight so that the horizontal and vertical lines are as close to 0 and 90 degrees as possible. Then convert the drawing with Orthogonality On ticked.

If your drawing is slightly skew, you can deskew it using Rotate Image by Degrees or Rotate Image by Line. Just a fraction of a degree is usually enough to deskew a drawing.

Raster image resolution

When scanning your drawing, you need to strike a balance between scanner resolution that is too low and scanner resolution that is too high. If the resolution is too low, there will not be enough information in the raster image and Scan2CAD will not be able to convert the image well. If the resolution is too high, the scanner will pick up every little blip and wobble in the drawing. Scan2CAD will convert all this detail, intentional or unintentional. Further, the raster image will be much larger than it needs to be, meaning that the image will take longer to convert.

The “right” resolution depends on the individual drawing but 200 to 300 dpi is right for most drawings.

The default settings in Scan2CAD’s Type Menu are intended for scans with a 200 to 300 dpi resolution. If you scan at a high resolution you may have to increase the Vector Hline/Vline Snap, Vector Corner Snap and Vector Pass-Through Snap which are measured in pixels.

Vectorisation settings

To get the best possible conversion results the vectorisation settings defined in the Type Menu must be optimal for the drawing or part of the drawing you are converting.

To find the best vectorisation settings for a particular drawing or part of a drawing, choose vectorisation settings and do a conversion using Vectorisation. Once you have inspected the vectors that have been created, Undo the vectorisation using UnDo Vectorisation in the Run Menu. Repeat with different vectorisation settings until you are happy with the results.

Below is a list of possible problems that can be rectified by changing the vectorisation settings. See the Type Menu for a full description of vectorisation settings.

If no arcs or circles are recognised, give the Arc Deviation Factor a value between 1 and 100 - try 75. If the Arc Deviation Factor is set to 0, no arcs will be recognised. The default Map and Sketch settings have the Arc Deviation Factor set to 0 so no arcs will be recognised unless you edit the Arc Deviation Factor.

If no polylines are created, tick Poly On. You can also create polylines using Make Polylines in the Edit Vector Menu whether Poly On is ticked or not. You can use Un-Make Polylines in the Edit Vector Menu to break polylines down into individual lines.

If too many short lines are created, increase the Line Deviation Factor or set it to 0 (auto).  A Line Deviation Factor of 0 will give optimal results in most cases. In the default Sketch settings, Line Deviation Factor is set to 1. This means that every blip and wobble in the raster image will be recognised. If you want less detail when converting a sketch, increase the Line Deviation Factor or set it to 0.

If you have lots of horizontal and vertical lines on your drawing, make sure that Orthogonality On is ticked.

Use the Outline or Scanline options in the Type Menu to convert solid black areas. Outline outlines solid areas, while Scanline converts them as series of horizontal parallel lines.

Remember, you can change the default Architectural, Electrical, Mechanical, CNC Profiles, Map, Sketch and Outline settings. See the Type Menu for details.

Is your image positive or negative?

Scan2CAD converts the black areas of an image. If your image is negative, i.e. what you want converted is displayed as white on a black background, click on Negative Image in the Edit Raster Menu before converting your image.

Error messages about temp files, creating files, writing files or allocating image memory

If you get any error messages about temp files, creating files, writing files or allocating image memory during a conversion, check the following:

•	Is your raster file stored on media that Scan2CAD can’t write to, like a CD or part of a network that you don’t have write access to? If so, copy the raster file to your hard drive and try again.

•	Check that you have free hard disk space on your PC.

See also

Deleting vectors so you can try the conversion again.

Possible problems with OCR conversions.


Possible problems with editing vectors

If you have problems editing vectors, check the following:

Grab Snap Distance

If you are editing or deleting text or using Move Grab Point, Move Grab Point Ortho, Split Line, Join Vectors, Curve to Line or Line to Curve you must make sure that the text, vector or grab point you are editing is within the Grab Snap Distance.

This is an outer square that appears around the pointer or cross hair cursor when you are editing vectors:

  or

If you are having trouble editing a vector or grab point, try increasing the Grab Snap Distance using Grab Snap Distance in the Edit Vector Menu or by pressing the 0, 1, 2, 4 or 8 number keys (the ones above QWERTY) on your keyboard. This sets the snap distance to 0, 1, 2, 4 or 8 pixels respectively.

When you are zoomed out, you won’t be able to see the Grab Snap Distance square around the cursor. In this case it is a good idea to zoom into the image to make sure that the vector or grab point you are trying to edit is within the Grab Snap Distance.

Is the line you are trying to edit part of a polyline?

Split Line, Join Vectors and Line to Curve don’t work on polylines. If one of these tools won’t work, the line you are trying to edit is probably part of a polyline.

C on your keyboard toggles vector colours on and off. If vector colours are on, polylines are displayed in green. Click on Un-Make Polylines in the Edit Vector Menu to turn polylines into lines so that you can edit them.

When you have finished editing, click on Make Polylines in the Edit Vector Menu to turn the lines back into polylines.

Is the line you are trying to edit a shallow arc?

If Split Line won’t work, make sure that the line you are trying to split is not in fact a shallow arc.

C on your keyboard toggles vector colours on and off. If vector colours are on, arcs are displayed in magenta. Use Curve to Line in the Edit Vector Menu to turn an arc into a line so that you can split it.

Is Attach Grab Points on or off?

If Move Grab Point is not behaving as you expected, it is likely that Attach Grab Points is turned off.

Check the Status Display at the bottom of the screen. If Attach Grab Points is turned off, the Status Display will read ATOFF. The A key on your keyboard toggles Attach Grab Points on and off.


Error messages about temp files, creating files, writing files or allocating image memory

If you get any error messages about temp files, creating files, writing files or allocating image memory, check the following:

•	Is your raster file stored on media that Scan2CAD can’t write to, like a CD or part of a network that you don’t have write access to? If so, copy the raster file to your hard drive and try again.

•	Check that you have free hard disk space on your PC.


Grab Points

Grab Points are vector end points, circle centre points, text origin points, arc mid points and circle 12 o’clock points.

G on your keyboard toggles the display of all grab points except polyline end points on and off. Vector end points, circle centre points and text origin points are shown as blank squares. Arc mid points and circle 12 o’clock points are shown as grey filled squares. Use Grab Point Size in the View Menu to make the squares bigger or smaller.

P on your keyboard toggles the display of polyline end points on and off. Polyline end points are displayed as green filled squares. Use Grab Point Size in the View Menu to make the squares bigger or smaller.

You can move grab points using Move Grab Point or Move Grab Point Ortho. You can join vectors by deleting the grab points between them and you can split a line by inserting a grab point at the split point.


Selecting an area using Window Mode

1.	If the cursor is not in Window Mode [image], click on [image], press the W key or choose Window Mode from the View Menu.

2.	Drag a rectangle around the area you want (drag top left to bottom right). The area you have selected will be marked by a dotted rectangle. If you are not satisfied with your selection simply drag another rectangle.

Once you have selected an area, you can:

Zoom into it.

Vectorise it.

Manipulate it using one of the following options from the Edit Raster Menu: Outline Image, Speckle Removal, Hole Removal, Thin Image, Ortho Thin Image or Thicken Image. Only the selected area will be affected by the option you choose.

Save it (raster image only).

After you have zoomed, vectorised, manipulated or saved, you will be zoomed in to the area you selected. To zoom back out so you can see the whole image, press the Home key. Click here for other zoom options.


Possible conversion problems

The vector image that is created by Scan2CAD may have one or more of the following problems. Click below for causes and solutions!

No text has been converted or text has been converted to lines and arcs instead of proper text.

Areas of text have not been converted.

Small text has not been converted.

Large text has not been converted.

Individual characters have not been converted.

Individual characters have been converted as question marks.

Text has been converted badly.

Text has been converted upside-down.

Numbers have been converted to letters.

Letters have been converted to numbers.

Text has been converted to higgeldy-piggeldy characters in different colours.

Non-text parts of the drawing have been recognised as text.

Vectorisation quality is generally poor.

Horizontal and vertical lines are slightly angled after conversion.

Too many small vectors are recognised.

No arcs or circles are recognised.

No polylines are created.

Error messages about temp files, creating files, writing files or allocating image memory.

If you want to convert a solid black area like a logo, see Outline and Scanline.

See also:

Deleting vectors so you can try the conversion again.


OCR

OCR stands for Optical Character Recognition. This means that Scan2CAD will recognise text on your drawing as proper text rather than recognise it as lines and arcs.


No text has been converted

If no vector text is recognised when Scan2CAD converts your raster image, check the following.

Conversion option

Scan2CAD will only recognise text if you convert your drawing using the OCR or All options.

Raster image quality

Zoom into the raster image and look at the text. What is the quality like? Do the letters run into each other as in the example below? If the quality of the raster text is poor, Scan2CAD will not be able to recognise it. “Garbage In, Garbage Out”!

If the quality of the raster text is poor, the only remedy is to start off with a better quality raster image. If this is not possible, you can either add the text manually in Scan2CAD (see Text) or later in your CAD program. You may want to erase areas of very poor quality raster text (see Area) so that these areas are not vectorised to lines and arcs.

Text size

Scan2CAD is unlikely to recognise text that is smaller than five pixels in size, or even text that is slightly larger than this where letters are complex. This is because where text is very small there are simply not enough pixels in each letter to adequately represent the letter so that it can be recognised.

Scan2CAD will also fail to recognise text if the Character Size Limit in OCR Settings is set incorrectly. If the Character Size Limit is too small, Scan2CAD will miss text that is larger than the Character Size Limit. If the Character Size Limit is too large, Scan2CAD may miss text even though it is smaller than the Character Size Limit. This is because it may think that the text is part of the drawing, not text.

Use OCR Char Size in the OCR Menu to set the Character Size Limit automatically.

To use OCR Char Size, zoom into a character that is representative of the text you want to convert. Then select OCR Char Size from the OCR Menu. Immediately after selecting OCR Char Size, click on the character you have zoomed into. The character will be surrounded by a rectangle and the Character Size Limit will automatically be updated to the size of the character you have just clicked on.

Fonts

By default, Scan2CAD can only recognise text that is written in standard fonts. These fonts are Arial, Sans Serif and Times New Roman. A sample file supplied with Scan2CAD, Text.Tif, shows the fonts that Scan2CAD has been trained to recognise. Scan2CAD may not recognise other fonts well. It may also fail to recognise Arial, Sans Serif and Times New Roman characters that are narrower or wider than standard.

If Scan2CAD cannot recognise the fonts on your drawings, you can train it to do so using the Scan2CAD Font Training Kit.

Vectorisation settings

If you converted your drawing using All and no text has been recognised, go to the Type Menu and see which option is ticked.

If Outline or Scanline are ticked, Scan2CAD won’t recognise text when you convert your drawing using All. To convert your drawing you need to use OCR first, then Vectorisation.

See also

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Areas of text have not been converted

If areas of text are not recognised when Scan2CAD converts your raster image, check the following.

Raster image quality

Zoom into the raster image and look at the text that has not been recognised. What is the quality like? Do the letters run into each other as in the example below? If the quality of the raster text is poor, Scan2CAD will not be able to recognise it. “Garbage In, Garbage Out”!

If the quality of the raster text is poor, the only remedy is to start off with a better quality raster image. If this is not possible, you can either add the text manually in Scan2CAD (see Text) or later in your CAD program. You may want to erase areas of very poor quality raster text (see Area) so that these areas are not vectorised to lines and arcs.

Text size

Scan2CAD is unlikely to recognise text that is smaller than five pixels in size, or even text that is slightly larger than this where letters are complex. This is because where text is very small there are simply not enough pixels in each letter to adequately represent the letter so that it can be recognised.

Scan2CAD will also fail to recognise text if the Character Size Limit in OCR Settings is set incorrectly. If the Character Size Limit is too small, Scan2CAD will miss text that is larger than the Character Size Limit. If the Character Size Limit is too large, Scan2CAD may miss text even though it is smaller than the Character Size Limit. This is because it may think that the text is part of the drawing, not text.

Use OCR Char Size in the OCR Menu to set the Character Size Limit automatically.

To use OCR Char Size, zoom into a character that is representative of the text you want to convert. Then select OCR Char Size from the OCR Menu. Immediately after selecting OCR Char Size, click on the character you have zoomed into. The character will be surrounded by a rectangle and the Character Size Limit will automatically be updated to the size of the character you have just clicked on.

Fonts

By default, Scan2CAD can only recognise text that is written in standard fonts. These fonts are Arial, Sans Serif and Times New Roman. A sample file supplied with Scan2CAD, Text.Tif, shows the fonts that Scan2CAD has been trained to recognise. Scan2CAD may not recognise other fonts well. It may also fail to recognise Arial, Sans Serif and Times New Roman characters that are narrower or wider than standard.

If Scan2CAD cannot recognise the fonts on your drawings, you can train it to do so using the Scan2CAD Font Training Kit.

See also

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Small text has not been converted

Scan2CAD is unlikely to recognise text that is smaller than five pixels in size, or even text that is slightly larger than this where letters are complex. This is because where text is very small there are simply not enough pixels in each letter to adequately represent the letter so that it can be recognised.

Small text is also particularly prone to being poor quality.

Zoom into the raster image and look at the small text that has not been recognised. What is the quality like? Do the letters run into each other as in the example below? If the quality of the raster text is poor, Scan2CAD will not be able to recognise it. “Garbage In, Garbage Out”!

If the quality of the raster text is poor, the only remedy is to start off with a better quality raster image. If this is not possible, you can either add the text manually in Scan2CAD (see Text) or later in your CAD program. You may want to erase areas of very poor quality raster text (see Area) so that these areas are not vectorised to lines and arcs.

See also:

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Large text has not been converted

Scan2CAD will not recognise text if it is larger than the Character Size Limit in OCR Settings in the OCR Menu. To remedy this problem, zoom into a character that is representative of the large text you want to convert. Then select OCR Char Size from the OCR Menu. Immediately after selecting OCR Char Size, click on the character you have zoomed into. The character will be surrounded by a rectangle and the Character Size Limit will automatically be updated to the size of the character you have just clicked on.

See also:

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Individual characters have not been converted

If individual characters are not recognised when Scan2CAD converts your raster image, check the following.

•	NOTE: You can manually insert individual text characters that Scan2CAD can’t convert using the Text function in Scan2CAD, or you can edit them later in a text editor like Windows Notepad or in your CAD program.

Raster image quality

If individual characters have been missed, zoom into the raster image and look at them. Do the characters run into each other? If the quality of the characters is poor, Scan2CAD will not be able to recognise them.

Character Size Limit

If Scan2CAD has missed larger text characters, you need to increase the Character Size Limit in OCR Settings in the OCR Menu.

For example, if the Character Size Limit is set to 54, the words EX. GARAGE in the example below will be recognised, but the brackets will not be. This is because the brackets are higher than 54 pixels.

To remedy this problem, zoom into one of the brackets. Then select OCR Char Size from the OCR Menu. Immediately after selecting OCR Char Size, click on the bracket you have zoomed into. The bracket will be surrounded by a rectangle and the Character Size Limit will automatically be updated to the size of the bracket you have just clicked on so that next time you run OCR, the brackets will be recognised.

Text position

If text is written over lines and arcs, Scan2CAD probably won’t be able to recognise it.

In this example, Scan2CAD won’t recognise the letter C. You can add the C after running OCR, by editing the POR  H text, using the Text function.

See also

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Individual characters have been converted as question marks

Characters that Scan2CAD is unsure about are displayed as question marks. The point at which Scan2CAD becomes unsure is the OCR Recognition Limit, which is set in OCR Settings. You can manually edit the question marks to the correct characters using the Text function in Scan2CAD, or you can edit them later in a text editor like Windows Notepad or in your CAD program.

See also:

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Text has been converted upside-down

If text is converted upside-down when Scan2CAD converts your raster image, check the character rotation that is set in OCR Settings.

Text can become very confusing when viewed from different orientations. For example, a q is a b when looked at upside-down. Where the text you are recognising is all at the same orientation you should set that orientation in OCR Settings to ensure that Scan2CAD will only try to recognise text the right way up.

Where you have text at different orientations, you can set the orientation to Auto. Scan2CAD will then make a judgement about the orientation of each piece of text it tries to recognise but some text may be recognised the wrong way up.

Where you have text at different orientations, it is a good idea to convert differently oriented text using different orientation settings. Scan2CAD will only convert text that is displayed on the screen. This means you can zoom into text that is at 90 degrees and convert it using a 90 degree orientation setting. You can then zoom into text that it at 0 degrees and convert it using a 0 degree orientation setting. To make this process quicker, there are short cut keys for setting orientation:

0 degrees	F1

90 degrees	F2

180 degrees	F3

270 degrees	F4

See also:

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Numbers have been converted to letters

Scan2CAD recognises text by means of technology called neural networks. It is supplied with two neural network options, Standard and User. You can choose between Standard and User in OCR Settings.

Standard recognises text that is written in standard fonts. It recognises both letters and numbers. User recognises numbers only.

If you have a drawing or an area of a drawing that contains numbers only, for example an area of dimensions, you should convert that drawing or drawing area with the User option ticked. Because the User option only recognises numbers, there is less likely to be confusion between similar numeric and non-numeric characters such as 6 and G.

See also:

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Letters have been converted to numbers

If Scan2CAD is converting all letters to numbers, you have probably ticked the User Character Set option in OCR Settings.

See also:

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Text has been converted to higgeldy-piggeldy characters in different colours

If the text that has been recognised is higgeldy-piggeldy and displayed in different colours, this is because Display Mode in OCR Settings is set to Chars. Click on Build Strings in the OCR Menu to join the individual characters together to make text strings.

See also:

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Non-text parts of the drawing have been recognised as text

If non-text parts of the drawing have been recognised as text, check the character rotation that is set in OCR Settings. If character rotation is set to Auto, Scan2CAD is more likely to recognise non-text parts of the drawing as text.

Where you have text at different orientations, it is a good idea to convert differently oriented text using different orientation settings rather than to use Auto. Scan2CAD will only convert text that is displayed on the screen. This means you can zoom into text that is at 90 degrees and convert it using a 90 degree orientation setting. You can then zoom into text that it at 0 degrees and convert it using a 0 degree orientation setting etc.

Because Scan2CAD only converts the part of the image that is displayed on the screen, you can also use OCR on areas of the drawing that contain text only. This way, Scan2CAD cannot recognise text where none exists in other parts of the drawing.

See also:

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Horizontal and vertical lines are slightly angled after conversion

If horizontal and vertical lines are slightly angled after conversion, you need to make sure that the drawing was scanned in straight. You will get much better vectorisation results if you scan the drawing in straight so that horizontal and vertical lines on the raster image are as close to 0 and 90 degrees as possible.

If your drawing is slightly skew, you can deskew it using Rotate Image by Degrees or Rotate Image by Line. Just a fraction of a degree is usually enough to deskew a drawing.

If you have lots of horizontal and vertical lines on your drawing, make sure that Orthogonality On is ticked.

See also:

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Too many small vectors are recognised

If Scan2CAD recognises too many small vectors, check the following:

Raster image quality

Zoom into the raster image and look at it. Are the raster lines clean and continuous? Or are they broken up? Do they contain white holes? If the lines in the original raster image are broken up, the vector lines that Scan2CAD creates will also be broken up. “Garbage In, Garbage Out”!

If the quality of the raster image is poor, try scanning the original drawing again. If this doesn’t give you a better quality raster image you can sometimes go some way to getting better results using Scan2CAD's raster editing tools. You can draw over individual badly-scanned raster lines or arcs using Raster Draw Mode. Use Speckle Removal to remove black speckles from white areas. Use Hole Removal or Thicken Image to fill white holes in black areas. If the lines are very thin, thicken them using Thicken Image.

Raster image resolution

You may have scanned the image in at too high a resolution.

When scanning your drawing, you need to strike a balance between scanner resolution that is too low and scanner resolution that is too high. If the resolution is too low, there will not be enough information in the raster image and Scan2CAD will not be able to convert the image well. If the resolution is too high, the scanner will pick up every little blip and wobble in the drawing. Scan2CAD will convert all this detail, intentional or unintentional. Further, the raster image will be much larger than it needs to be, meaning that the image will take longer to convert.

The “right” resolution depends on the individual drawing but 200 to 300 dpi is right for most drawings.

Vectorisation settings

Try increasing the Line Deviation Factor or setting it to 0 (auto). A Line Deviation Factor of 0 will give optimal results in most cases. In the default Sketch settings, Line Deviation Factor is set to 1. This means that every blip and wobble in the raster image will be recognised. If you want less detail when converting a sketch, increase the Line Deviation Factor or set it to 0.

See also

Deleting vectors so you can try the conversion again.

Possible conversion problems.


No arcs or circles are recognised

If no arcs or circles are recognised, give the Arc Deviation Factor a value between 1 and 100 - try 75. If the Arc Deviation Factor is set to 0, no arcs will be recognised. The default Map and Sketch settings have the Arc Deviation Factor set to 0 so no arcs will be recognised if you use these defaults unless you edit the Arc Deviation Factor.

See also:

Deleting vectors so you can try the conversion again.

Possible conversion problems.


No polylines are created

If no polylines are recognised, tick Poly On. You can also create polylines using Make Polylines in the Edit Vector Menu whether Poly On is ticked or not. You can use Un-Make Polylines in the Edit Vector Menu to break polylines down into individual lines.

See also:

Deleting vectors so you can try the conversion again.

Possible conversion problems.


Deleting vectors so you can try a conversion again

Click on UnDo OCR in the Run Menu to delete the text that was recognised last time you used OCR or All.

Click on UnDo Vectorisation in the Run Menu to delete the vectors that were recognised last time you used Vectorisation or All.

Click on Close Vector in the File Menu to delete all text and vectors.

See Vector Erase Mode for details of deleting individual vectors and all vectors in an area.


Font Training Kit

By default, Scan2CAD can only recognise text that is written in standard fonts. These fonts are Arial, Sans Serif and Times New Roman. A sample file supplied with Scan2CAD, Text.Tif, shows the fonts that Scan2CAD has been trained to recognise. Scan2CAD may not recognise other fonts well. It may also fail to recognise Arial, Sans Serif and Times New Roman characters that are narrower or wider than standard.

If Scan2CAD cannot recognise the fonts on your drawings, you can train it to do so using the Scan2CAD Font Training Kit. For details on the Font Training Kit, please contact your Scan2CAD supplier or:

Softcover International Ltd

320 Old Brompton Road

London SW5 9JH

UK

Email:

postmaster@softcover.com

Phone:

0171 259 2100 from inside the UK

00 44 171 259 2100 from outside the UK

Fax:

0171 373 6368 from inside the UK

00 44 171 373 6368 from outside the UK

Web site addresses:

www.softcover.com

www.rastertovector.com


Tutorial

We recommend that you do this brief step-by-step introduction to using Scan2CAD. It takes approximately 40 minutes to work through and shows you Scan2CAD’s most important tools.

This tutorial assumes that you have just installed Scan2CAD and that you have not yet changed any of the system defaults.

Do the parts of the tutorial that are indented and labelled (a), (b), (c) etc. Other parts of the tutorial are just there to give you information, not to do.

You can either do this tutorial on-screen, or you can print it out and work through it.

To do the tutorial on-screen, go to the Help Menu in the Help Window and choose Always on Top. If your Help Menu doesn’t contain this option, go to the Options Menu in the Help Window and choose Keep Help on Top, then choose On Top. This will keep the Help on top of the Scan2CAD screen even as you work in Scan2CAD. You should also resize the Help Window so that it doesn’t take up too much of the screen.

To print the tutorial out, go to the File Menu in the Help Window and select Print Topic. The tutorial prints to approximately 15 sheets of paper.

1.	Opening the raster file you want to convert

a)	Click on the File Menu.

The File Menu is divided into two parts. The top part is for loading and saving raster files. The bottom part is for loading and saving vector files.

b)	Click on Open Raster File. The Open Raster File dialogue box appears.

c)	Click on the sample raster file Flrplan.Tif which is supplied with Scan2CAD. Flrplan.Tif can be found in your Scan2CAD directory, normally c:\scan2cad.

d)	Click on OK. Flrplan.Tif appears on the screen, displayed in black.

•	VERY IMPORTANT NOTE: Scan2CAD ONLY opens MONO (i.e. BLACK and WHITE or LINE ART) images.

99% of all Scan2CAD support calls are from users attempting to open Greyscale or Colour raster files. Save yourself this problem. Remember, when you scan drawings for vectorisation in Scan2CAD, you must create and save MONO images only!

Scan2CAD supports the following file formats: PCX, IMG, BMP and TIFF. It supports the following types of TIFF file: Uncompressed, Packbits, Fax Group 3 and Fax Group 4.

2.	Zooming and panning

This section shows you the quickest and most useful methods of zooming in and out of the image on the screen.

Magnifying and Demagnifying

a) 	Position your cursor on any part of the image you want to see in more detail.

b) 	Press M on your keyboard.

Scan2CAD zooms in around the cursor position.

c) 	Press D on your keyboard.

 Scan2CAD zooms out around the cursor position.

Viewing the whole image

a) 	Press your Home key. (If you press the Home key on your numeric keypad, Num Lock must be off).

Scan2CAD zooms out so you can see the whole image on the screen.

Zooming into a selected area

a)	If the cursor does not look like this [image] (Window Mode), click on [image] or press the W key on your keyboard.

b)	Place the cursor at the top left corner of the area you want to zoom into. Hold down your left mouse button and drag the cursor to the bottom right corner of the area you want to zoom into. Then release your left mouse button.

The area you have selected will be marked by a dotted rectangle. If you are not satisfied with your selection repeat step b.

c)	Press * on your numeric keypad.

Scan2CAD zooms into the exact area you have selected. No additional part of the image is displayed. This means that the right hand and/or bottom parts of the screen around the zoomed area may be grey.

d)	Press F on your keyboard.

This accesses the Fill command, which increases the amount of the image that is displayed to fill the screen. Any grey area disappears.

•	NOTE: If you convert the raster file when you are zoomed in, only the displayed part of the image will be converted.

Going back to the previous view

a)	Double-click on your right mouse button.

b)	Double-click on your right mouse button again.

c)	Double-click on your right mouse button again.

When you double-click your right mouse button, Scan2CAD steps back through the various zooms you have done.

Panning

a)	Drag the Scroll Bars to pan left, right, up or down.

b)	Press the Arrow Keys to pan left, right, up or down incrementally.

c)	Press the Arrow Keys at the same time as the [Ctrl] key to pan left, right, up or down by a page.

d)	To pan to a specific position on the image, place your cursor at that position and then press the Z key.

3.	Editing the raster image

If the quality of the raster image is poor, Scan2CAD will not be able to convert it well: “Garbage In - Garbage Out”!

You can sometimes improve the quality of a raster image by editing it before conversion. You can do this using the commands in the Edit Raster Menu and the Edit Icons above the screen.

Particularly useful commands in the Edit Raster Menu are:

•	Speckle Removal - removes black speckles from white areas.

•	Hole Removal - removes white speckles from black areas.

•	Thicken Image - thickens very thin raster lines. Can also remove white speckles from black areas.

•	Rotate Image by Degrees and Rotate Image by Line - let you rotate the raster image by a few degrees or a fraction of a degree to deskew it if it has not been scanned in straight.

Another particularly useful raster editing command is Raster Erase Area. This deletes an area of the raster image inside a rectangle. Try it on a part of Flrplan.Tif:

a) 	Press your Home key to zoom out so you can see the whole image. (If you press the Home key on your numeric keypad, Num Lock must be off).

b)	Click on the [image] icon to choose raster editing (the eighth icon from the left).

c)	Click on [image] to choose erase.

d)	Click on [image] to choose area.

e)	Position the cursor above and to the left of the word KITCHEN. Hold down your left mouse button and drag a box diagonally to below and to the right of the word KITCHEN. Release your left mouse button.

The part of the raster image inside the box you dragged is deleted.

This is a very useful way of deleting dirty or smudged areas of the raster image.

f)	Click on [image] to restore the area you erased. This undoes your last action only.

4.	Converting Text - OCR (Optical Character Recognition)

Scan2CAD recognises and converts lines, polylines, arcs, circles and text.

When you are converting a drawing that contains text it is a good idea to convert the text first using OCR. Once you are happy with the text conversion, convert the rest of the drawing (see Step 5).

Scan2CAD only converts the text that is displayed on the screen. This means that you can convert different text using different text conversion settings.  For example, you can zoom into text - say the title of the drawing - and convert it using a character rotation of 0 and the Standard character set. Then you can zoom into an area of vertical dimensions where the numbers are oriented at 90 degrees. You can convert this area using a character rotation of 90 and the User character set, which only recognises numbers. Converting a drawing in parts like this will give you more accurate text recognition.

However in this Tutorial you are going to convert all the text on the drawing in one go.

Selecting OCR settings

The way that Scan2CAD converts text is controlled by OCR settings.

a)	Click on the OCR Menu. Click on OCR Settings.

The OCR Settings dialogue box appears. Note the Character Size Limit. It is important to set this correctly or Scan2CAD may fail to recognise some text. You are going to set the Character Size Limit automatically, using OCR Char Size.

b)	Click on Cancel to close the OCR Settings dialogue box.

c) 	Place your cursor over the first “B” in the word BEDROOM in the top left hand room of the image (it does not matter what shape the cursor is).

d)	Press M to magnify.

e)	Press M to magnify several times.

f)	Click on the OCR Menu. Click on OCR Char Size.

g)	Click on the first “B” in “BEDROOM”. A rectangle appears around the “B”.

h)	Click on the OCR Menu. Click on OCR Settings.

Note that the Character Size Limit is now set to 52. When you clicked on OCR Char Size and then on B, Scan2CAD measured the height of the letter B in pixels and automatically inserted this height plus a small percentage as the Character Size Limit.

i)	Make sure that the values in the OCR Settings dialogue box are set as follows:

Character Size Limit	52

This size must be correct or Scan2CAD may fail to recognise the text.

Character Rotation 	0

As all of the text you are going to convert is at 0 degrees, you should choose 0.

OCR Recognition Limit	10

If Scan2CAD is more than 10% sure about the identity of a specific character, it will write that character. Otherwise it will write a ?.

Character Set	Standard

This recognises alphanumeric characters written in standard fonts.

Display Mode	Strings

Scan2CAD will recognise text as strings (lines of text) not as individual characters.

j)	Click on OK to accept the values in the OCR Settings dialogue box.

Doing the conversion

a) 	Because you are going to convert the text on the whole image, make sure the whole image is displayed by pressing your Home key. (If you press the Home key on your numeric keypad, Num Lock must be off).

b)	Click on the [image] icon - the third icon from the right.

This converts the text in the part of the raster image displayed on the screen into editable vector text. The converted text appears in magenta. The conversion will take a short while.

When the text has been converted, a message box containing a Help button may appear.

c) 	If this message box appears, click on the Help button.

A Help window containing a list of things that might go wrong during a raster to vector conversion appears. If you ever have problems converting an image, refer to this list. You can also reach this list by clicking on the Scan2CAD Help Menu and then clicking on Contents. In the Help Contents page, choose Possible Conversion Problems.

d)	Close down the Help window and click on OK to close the message box.

Viewing the raster image, the vector image and both images

a)	Click on the [image] icon (4th from left), or press V on your keyboard.

The raster file will be turned off so you can only see the vector file (the magenta text) on the screen.

b)	Click on the [image] icon (3rd from left), or press R on your keyboard.

The vector file will be turned off so you can only see the raster file on the screen.

c)	Click on the [image] icon (5th from left), or press B on your keyboard.

The vector file will appear superimposed over the raster file.

Editing vector text

You are now going to edit some of the text that Scan2CAD has recognised. First, zoom into the part of the file you are going to edit.

a)	Place your cursor in the bottom right part of the image over the last “N” of “PROPOSED STUDY EXTENSION”.

b)	Press M on your keyboard to magnify.

c)	Press M again to magnify further.

You will see that the “PROPOSED STUDY EXTENSION” text has converted well but the smaller text around it has not.

d)	Place your cursor over the “X” in “REUSED EX. WINDOW”.

e)	Press M on your keyboard to magnify.

f)	Press M again to magnify further.

If you look at this smaller text you will see that it is not good quality. The letters it is made up of are not well defined and run into each other. Scan2CAD can only recognise good quality text. “Garbage In - Garbage Out”!

You are now going to edit some of the vector text.

g)	Click on [image] to choose vector text editing.

h)	Click on the magenta vector text “0 ?. WN1” that is displayed over the black “REUSED EX. WINDOW” text.

i)	The text dialogue box appears. The text 0 ?. WN1 is shown in the dialogue box.

j)	Overtype the text with REUSED EX. WINDOW.

k)	Press Enter or click on OK.

The text you have just typed appears on the screen, replacing the original text.

You are now going to move the text you have just edited to the left so that it is in the correct position.

l)	Press G on your keyboard to switch grab points on.

Grab points are points that you can use to move or manipulate vectors. They are shown on the screen as squares. A grab point appears below the magenta “R” of the vector “REUSED EX. WINDOW”.

m)	Click on [image] to choose Move Grab Point.

n)	Position your cursor on the grab point and hold down your left mouse button. Drag your cursor to the left. As you drag your cursor you will see it is attached to a rubber banded line.  When your cursor is just to the left of and below the black “R” of the raster “REUSED”, release your left mouse button. The text is moved.

o)	Press G on your keyboard to switch grab points off.

p) 	Press your Home key to zoom out so you can see the whole image. (If you press the Home key on your numeric keypad, Num Lock must be off).

Finishing the text recognition

You have now converted and saved the text elements of the drawing.

When you are converting a drawing “for real”, you might want to finish text recognition by editing or deleting poorly recognised text before converting the rest of the drawing. Don’t do this now!

When you are converting a drawing “for real”, you may also want to delete areas of raster text that have been poorly recognised using the Raster Erase Area method described in Step 4. If you do not do this, this text might be recognised as small lines and arcs when you convert the rest of the drawing. Don’t do this now!

5.	Converting lines, arcs and circles

You are now going to convert the lines, arcs and circles on the drawing.

Scan2CAD only converts the part of the drawing that is displayed on the screen. This means that you can convert different parts of the drawing using different conversion settings. In this Tutorial you are going to convert the whole drawing in one go.

Selecting conversion settings

The way that Scan2CAD converts a drawing is controlled by vectorisation settings.

For successful conversion, different drawings and applications need different vectorisation settings. For example, architectural floorplans tend to be made up of horizontal and vertical lines and Scan2CAD needs to try to keep these lines exactly horizontal and vertical (orthogonal). Maps on the other hand are made up of lines that go in all directions (non-orthogonal) and Scan2CAD must not try to make these lines exactly horizontal and vertical.

Scan2CAD is supplied with default vectorisation settings for converting different types of drawings. These default settings work well for most drawings but can be edited if necessary. To choose default vectorisation settings:

a)	Click on the Type Menu. This contains the default settings.

b)	Click on Architectural. This is the default setting type that best describes Flrplan.Tif.

c)	The Vectorisation Settings dialogue box appears. Click on OK to accept the default architectural drawing conversion settings.

Doing the conversion

a) 	Because you are going to convert the whole image, make sure the whole image is displayed by pressing your Home key. (If you press the Home key on your numeric keypad, Num Lock must be off).

b)	Click on the [image] icon - the second icon from the right.

Flrplan.Tif is converted to vectors. This will take a short while.

The [image] icon converts the raster image to lines, polylines, arcs and circles. It ignores areas of the raster image where text has already been found using OCR - these areas are “masked”. Any areas where you have deleted text that OCR recognised, or where you have typed new text manually, are not masked and Scan2CAD will convert any raster parts of the image in these areas to lines, polylines, arcs and circles. The T key toggles masked area display on and off. Masked areas are shown as dashed boxes around text.

c) 	Click on OK to close the message box with the Help button.

The lines, arcs and circles on the Flrplan.Tif drawing are converted and are displayed in red. The vector data is displayed over the raster drawing. This is called Raster Overlay.

•	NOTE: You can undo a conversion by selecting UnDo Vectorisation from the Run Menu.

6.	Viewing line colours, grab points and cursors

a)	Turn off the raster file by clicking on the [image] icon or by pressing V on your keyboard.

Line colours

Unless you have changed Scan2CAD’s defaults, arcs, circles, lines and polylines are all displayed in red.

a)	Press C on your keyboard.

Lines are still displayed in red, but arcs are displayed in magenta, circles in blue and polylines in green. (There are no circles in this drawing. There are also no polylines as polyline creation is switched off in the default architectural vectorisation settings).

b)	Press C on your keyboard to switch line colours off.

c)	Press C on your keyboard to switch line colours on again.

Grab Points

Grab points are points that you can use to move or manipulate vectors. When displayed, they appear on the screen as squares.

a)	Press G on your keyboard.

Grab points will appear at vector end points, circle centre points, text origin points, arc mid points and circle 12 o’clock points. The grab points at vector end points, circle centre points and text origin points will appear as blank squares. The grab points at arc mid points and circle 12 o’clock points will appear as grey squares.

b)	Press G on your the keyboard to switch grab points off.

c)	Press G on your keyboard to switch grab points on again.

d)	Click on the View Menu, then click on Grab Point Size.

By default, grab point size is set at 2.

e)	Click on 4.

The grab point squares on the screen become larger. A larger grab point size makes it easier for you to grab vectors and to edit them without zooming in. As you zoom in the grab point size remains constant on screen.

f)	Place the cursor anywhere on the screen in the centre of a concentration of grab points.

g)	Press M on your keyboard to magnify.

h)	Press M several times.

The size of the grab point squares remains constant.

i) 	Press your Home key to view the whole image. (If you press the Home key on your numeric keypad, Num Lock must be off).

•	NOTE: In the same way that G toggles line, arc, circle and text grab points on and off, P toggles polyline grab points. These mark the ends of polylines and are displayed as green filled squares. Polyline grab point size is controlled by Grab Point Size in the View Menu.

Cursor type

Whenever you use a vector editing function, the cursor changes to a pointer that looks like this:

 or [image] or

Or to a cross-hair “guide line” cursor that looks like this:

or [image] or

Where there are two boxes around the cursor point or cross, the smaller box is the size of one pixel on the raster image. The larger box shows the Grab Snap Distance (see Step 7).

Where there is only one box, this is because the Grab Snap Distance is just one pixel in size, so the two boxes are superimposed.

Where there are no boxes, this is because the size of one pixel is too small to see - you need to zoom in to see the boxes.

a)	Click on [image] - the Move Grab Point icon.

The cursor changes to a pointer.

b)	Click on the View Menu, then on Cursor Type.

c)	Click on Guide Line.

The cursor changes into a cross-hair cursor with screen-wide guide lines. This guide line cursor is very useful when you are editing vectors because it shows you whether vectors in different parts of the image are aligned.

d)	Turn the raster file back on by clicking on the [image] icon or pressing B on your keyboard.

7.	Editing vectors with SnapTidy tools

You are now going to zoom into a part of the vectorised image and edit the vectors in it using Scan2CAD’s SnapTidy tools.

a)	If the cursor does not look like this [image] (Window Mode), click on [image] or press the W key on your keyboard.

b)	Place the cursor at the top left corner of the area surrounded by the thick line on the screenshot below. Hold down your left mouse button and drag the cursor to the bottom right corner of this area. Then release your left mouse button.

The area will be marked by a dotted rectangle. If you are not satisfied with your selection repeat step b.

c)	Press * on your numeric keypad to zoom into the area you have selected:

The numbers on the diagram above refer to the red vector lines. You will see that line 2 is lower than line 1. You are going to edit line 2 so it is aligned with line 1.

d)	Ensure that the Status Message at the bottom of the screen reads ATON. If it reads ATOFF, press A on your keyboard.

e)	Click on [image] to select Move Grab Point.

The cursor changes to the guide line cursor.

f)	Position the cursor as shown in the diagram above so that the horizontal cross-hair is on top of line 1 and the vertical cross-hair is on top of line 3 (when the cross-hairs are exactly on top of the lines, the lines look blue or green). The grab point (square) at the junction of lines 2 and 3 must be inside the Grab Snap Distance - the larger box around the cursor.

g)	Click with your left mouse button.

The grab point at the junction of lines 2 and 3 moves up so that it is aligned with line 1. The old position of line 2 is shown in white or grey.

•	NOTE: If the edit has not gone as expected, you can undo it by clicking on [image]. This only undoes your last action.

h)	Click on [image] to select Move Grab Point Ortho.

For the next piece of editing you are going to do, you need a bigger Grab Snap Distance box around the cursor. You can change the Grab Snap Distance by pressing the 0, 1, 2, 4 or 8 number keys (the ones above QWERTY) on your keyboard. This sets the snap distance to 0, 1, 2, 4 or 8 pixels respectively.

i)	Press the number 8 key (the one above the U and I keys).

The Grab Snap Distance box increases in size.

j)	Position the cursor as shown in the diagram below so that the horizontal cross-hair is on top of line 1 and the vertical cross-hair is on top of line 4 (when the cross-hairs are exactly on top of the lines, the lines look blue or green). The grab points (squares) at the junctions of lines 2 and 4 and lines 2 and 5 must be inside the Grab Snap Distance.

k)	Click with your left mouse button.

l)	Press * to redraw the screen. This deletes the white or grey lines displayed at the old positions of the lines and grab points.

Because you are using Move Grab Point Ortho, not Move Grab Point, line 2 and the junctions between lines 2 and 4 and lines 2 and 5 are correctly updated:

•	NOTE: If you were using Move Grab Point, the junction between lines 2 and 4 would have been moved exactly on top of the junction between lines 2 and 5, and line 5 would no longer have been vertical.

l)	Zoom out to view the entire image by pressing your Home key. (If you press the Home key on your numeric keypad, Num Lock must be off).

m)	If the cursor does not look like this [image] (Window Mode), click on [image] or press the W key on your keyboard.

n)	Place the cursor at the top left corner of the area surrounded by the thick line in the screenshot below. Hold down your left mouse button and drag the cursor to the bottom right corner of this area. Then release your left mouse button.

The area will be marked by a dotted rectangle. If you are not satisfied with your selection repeat step n.

o)	Press * on your numeric keypad to zoom into the area you have selected:

You will see that the door swing is made up of two vectors - a magenta arc and a short red line. You are going to join the arc and the short line to give a single arc.

p)	Click on [image] to select Join Vectors. This joins two vectors by deleting the grab point between them.

q)	Position the cursor as shown in the diagram above, over the grab point (square) between the arc and the line.

r)	Click with your left mouse button.

The arc and line are merged to give a single arc.

You have only tried a few of Scan2CAD’s powerful SnapTidy tools in this tutorial. For more details of Scan2CAD’s SnapTidy tools and for more examples of their use, look up the following commands in your manual or Help:

Move Grab Point

Split Line

Join Vectors

Curve to Line

Line to Curve

s)	Zoom out to view the entire image by pressing your Home key. (If you press the Home key on your numeric keypad, Num Lock must be off).

t)	Save the vector file by clicking on the File Menu then clicking on Save As DXF.

If you are using the Scan2CAD evaluation version a warning message about Save As DXF being restricted will appear. Click on OK to pass this message.

Save your file under the name Tute1.Dxf. Click on Save. The DXF file is now ready for import into your CAD program.

If you are using the Scan2CAD evaluation version, only the centre part of the vector file will have been saved. The part of the file that has been saved will be surrounded by a square.