Copyright: Copyright © 1998 Mario M. Westphal


START_PAGE

Copyright © 1998 Mario M. Westphal
All rights reserved.

Please read the information about License and Copyright before you use this software!

Information about how to register your personal copy of IMatch can be found under The Shareware Principle and Registration of IMatch.

The newest version of IMatch and additional information, tips & tricks can always be found at http://www.mwlabs.de.

What is IMatch all about?

Many people today have to deal with large libraries of stock photography or images libraries created from postings to the World Wide Web or the Usenet. Whenever it comes to actually finding an image in one of these libraries, whether by color, texture or a specific shape, the trouble begins.

Although there are numerous applications for creating and maintaining image libraries (so-called thumbnailing applications) all of these tools lack the ability to actual perform queries on these libraries. The best you can get is a feature that allows you to assign keywords or descriptions to each individual image and to perform queries to find all images matching a specific set of keywords.

In the last several years, the research field of Visual Information Retrieval brought up some new and fascinating approaches for querying image libraries by image content. These new algorithms are now available in some sophisticated high-end products, often included in databases from large vendors.

The target market for these high price products are professional uses in education, marketing and the industry.

IMatch is probably the first application that allows you to use the same techniques in an easy-to-use environment on your desktop. When you have large images libraries or CD-ROM's with images, you'll gonna like IMatch. It allows you to index all the images on your hard disk and external storage media and to query these databases by image content, color, texture, and shape.

You are now able to:

•	perform image queries against all images stored on your disks

•	find images with similar colors, textue and shape

•	clean up your image libraries by removing duplicate images, even if they have been renamed, cropped, resized or converted into another file format

•	find images that match a given sample within seconds, automatically, without any user intervention

•	drag the results directly from the IMatch Result Window into your favorite imaging application

Although being very powerful, IMatch is quite easy to handle. The image matching capabilities built into the system are hidden below a nice and easy to use user interface. Within minutes you will be able to understand and handle the system.

The completely new developed algorithms used in the IMatch Engine are tuned not only to be as good as possible with respect to image matching , but also to be fast enough to perform queries against very large image databases in only a few seconds.
On a current PC (Intel Pentium II, 333 MHz) IMatch is able to match a sample image against a database holding about 20.000 images in only 5 seconds!

Please follow this topic outline to learn more about IMatch:

 Image Matching, not an exact science...

 Creating and maintaining databases

 Matching images with a databases

 The IMatch result window

 Supported file formats

 Tips and Tricks


License and Copyright

IMatch and the IMatch Engine
Copyright © 1998 Mario M. Westphal.
All Rights Reserved.

SHAREWARE

Shareware distribution gives users a chance to try software before buying it. If you try a Shareware program and continue using it, you are required to register it (or purchase the licensed version as in the case of IMatch).

Copyright laws apply to both Shareware and retail software, and the copyright holder retains all rights, with a few specific exceptions as stated below. Shareware authors are accomplished programmers, just like retail authors, and the programs are of comparable quality. (In both cases, there are good programs and bad ones!)

Shareware is a distribution method, not a type of software. You should find software that suits your needs and pocketbook, whether it's retail or Shareware. The Shareware system makes fitting your needs easier, because you can try before you buy. And because the overhead is lower, prices are lower also.

Shareware has the ultimate money-back guarantee -- if you don't use the product, you don't pay for it.

LIMITED WARRANTY AND DISCLAIMER OF WARRANTY

THIS SOFTWARE AND ACCOMPANYING WRITTEN MATERIALS (INCLUDING INSTRUCTIONS FOR USE) ARE PROVIDES "AS IS" WITHOUT WARRANTY OF ANY KIND. FURTHER, Mario M. Westphal DOES NOT WARRANT, GUARANTEE, OR MAKE ANY REPRESENTATIONS REGARDING THE USE, OR THE RESULTS OF USE, OF THE SOFTWARE OR WRITTEN MATERIALS IN TERMS OF CORRECTNESS, ACCURACY, RELIABILITY, CURRENTNESS, OR OTHERWISE. THE ENTIRE RISK AS TO THE RESULTS AND PERFORMANCE OF THE SOFTWARE IS ASSUMED BY YOU. IF THE SOFTWARE OR WRITTEN MATERIALS ARE DEFECTIVE YOU, AND NOT Mario M. Westphal OR ITS DEALERS, DISTRIBUTORS, AGENTS, OR EMPLOYEES, ASSUME THE ENTIRE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

THE ABOVE IS THE ONLY WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, THAT IS MADE BY Mario M. Westphal, ON THIS PRODUCT. NO ORAL OR WRITTEN INFORMATION OR ADVICE GIVEN BY Mario M. Westphal, ITS DEALERS, DISTRIBUTORS, AGENTS OR EMPLOYEES SHALL CREATE A WARRANTY OR IN ANY WAY INCREASE THE SCOPE OF THIS WARRANTY AND YOU MAY NOT RELY ON ANY SUCH INFORMATION OR ADVICE.

NEITHER Mario M. Westphal NOR ANYONE ELSE WHO HAS BEEN INVOLVED IN THE CREATION, PRODUCTION OR DELIVERY OF THIS PRODUCT SHALL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL OR INCIDENTAL DAMAGES (INCLUDING DAMAGES FOR LOSS OF BUSINESS PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, AND THE LIKE) ARISING OUT OF THE USE OR INABILITY TO USE SUCH PRODUCT EVEN IF Mario M. Westphal HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

In other words: THERE IS NO GUARANTEE! YOU USE THIS SOFTWARE PRODUCT ON YOUR OWN RISK!

IF YOU DON'T LIKE THIS, SIMPLY DON'T USE IMatch!

IN STATES/COUNTRIES WHERE THESE RESTRICTIONS ARE ILLEGAL, YOU ARE NOT ALLOWED TO USE IMatch!

ACKNOWLEDGMENT

BY USING THE SHAREWARE VERSION OF IMatch YOU ACKNOWLEDGE THAT YOU HAVE READ THIS LIMITED WARRANTY, UNDERSTAND IT, AND AGREE TO BE BOUND BY ITS' TERMS AND CONDITIONS. YOU ALSO AGREE THAT THE LIMITED WARRANTY IS THE COMPLETE AND EXCLUSIVE STATEMENT OF AGREEMENT BETWEEN THE PARTIES AND SUPERSEDE ALL PROPOSALS OR PRIOR AGREEMENTS, ORAL OR WRITTEN, AND ANY OTHER COMMUNICATIONS BETWEEN THE PARTIES RELATING TO THE SUBJECT MATTER OF THE LIMITED WARRANTY.

Copyrights

IMatch, the IMatch Engine and this documentation
Copyright © 1998 Mario M. Westphal
All rights reserved.

The JPEG decoder used within this software is based on the Independent JPEG Group's JPEG software.
This software is the work of Tom Lane, Philip Gladstone, Jim Boucher, Lee Crocker, Julian Minguillon, Luis Ortiz, George Phillips, Davide Rossi, Guido Vollbeding, Ge' Weijers, and other members of the Independent JPEG Group.

The PNG decoder is based on the PNG Reference Library.
Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc., (c) 1996, 1997 Andreas Dilger, (c) 1998 Glenn Randers-Pehrson

PNG uses the ZLIB compression library created and maintained by Jean-loup Gailly and Mark Adler.
(C) 1995-1998 Jean-loup Gailly and Mark Adler.

TIFF decoder Copyright (c) 1988-1997 Sam Leffler, Copyright (c) 1991-1997 Silicon Graphics, Inc.

This software contains paintlib code. paintlib is copyright (c) 1996-1998 Ulrich von Zadow.

License

You may use the shareware version of IMatch for a 30 day trial period. If you would like to continue to use the product after the 30 day trial period, you are required to purchase the licensed version of IMatch. See The Shareware Principle and Registration of IMatch for further details an how to license your personal copy of IMatch.

Trademarks

Microsoft, Windows, Win32, Win32s, Windows NT, Windows 95, Visual C++, Visual Basic and Visual Studio are either trademarks or registered trademarks of the Microsoft Corporation.

WinZip is a registered trademark of Nico Mak Computing, Inc.

PaintShop Pro is a (registered) trademark of Jasc Software Inc.

ThumsPlus is a registered trademark of Cerious Software, Inc.

Various other product names mentioned in passing are trademarks or service marks of their respective owners.


The Shareware Principle and Registration of IMatch

See also License and Copyright

You may use the shareware version of IMatch for a 30 day trial period. If you would like to continue to use IMatch after the 30 day trial period, you are required to purchase the licensed version of IMatch.

You should carefully read the terms and conditions stated under License and Copyright before using this software.

The Author

Mario M. Westphal
Pestalozzistraße 6-12
61250 Usingen
Germany

Email: mariow@mwlabs.de
Homepage: http://www.mwlabs.de

Restrictions in the trial version

The free evaluation version of IMatch comes with all functions enabled and the complete online documentation. The unregistered version displays reminder screens (nag screens) from time to time to remind you to register the product if you continue to use it after the trial period.

Licensing IMatch

One licensed copy of IMatch may be used by a single person who uses the software personally on one or more computers.
You may access the licensed version of IMatch through a network, provided that you have obtained individual licenses for the software covering all workstations that will access the software through the network. For instance, if 5 different workstations will access IMatch on the network, each workstation must have its own IMatch license, regardless of whether they use IMatch at different times or concurrently.

How to obtain a license

The install directory of IMatch contains a file named REGISTER.WRI. This file contains the latest info on how to register your copy IMatch.

Performing the registration

To register your personal copy of IMatch, follow these simple steps:

1. 	Register with the registration provider as described in the file REGISTER.WRI

2. 	Start IMatch and switch to the [About] Tab

3. 	Click on the button Register

4. 	Enter your username and license code exactly as received after the registration

5. 	Press Register to perform the registration

When the username and license code entered are correct, IMatch will convert itself into a full version without any restrictions or reminder screens.


Purpose of the program

IMatch allows you to create databases containing descriptions of the images on your hard disk and other storage media. Once a database has been created, it can be queried by image content. This is the new and exiting feature that differentiates IMatch from other imaging applications.

Imagine the following scenarios:

•	You got a picture of a very bright and colorful sunset and you wonder if you have other images in your library with the same kind of color or texture.

•	You have downloaded a bunch of images from the World Wide Web or the Usenet and want to remove duplicate images already in your image library, even if these images have been cropped, renamed, resized, or converted into another file format.

•	You want to compose a new image and are looking for images that fit in color to a given sample image.

Without IMatch you would have to scan all your images by hand with a image application or browse through the thumbnails created by a thumbnail application. Anyway, this would be a very time consuming, boring and probably unsuccessful task. Especially when you have more than several hundred images, it is nearly impossible do find duplicate or similar pictures manually in a reasonable amount of time.

This is when IMatch comes in. IMatch is a new kind of image processing tool, with a strong focus on image retrieval by image content.

IMatch is not intended to replace image processing applications like PhotoShop, Paint Shop Pro or thumbnail applications like ThumbsPlus. IMatch enhances the capabilities of these applications by allowing you to query large collections of images by content, color, or texture. The results of such a query can then be processed with your favorite image application.

IMatch completely integrates with the Windows shell and enables you to communicate with other applications via drag and drop and the Windows clipboard. This allows IMatch to interoperate with all existing and upcoming Windows compatible applications.

»Image Matching: Not an exact science...«

Humans are able to »match« images quite easily. When you show a person an image of a green tree, a blue sky and some birds in the background, he (or she) will be able to find similar images in a image library without to much effort.

For a computer is it far more difficult to do the same job. Computers are dumb, you know...

First of all, for a computer a picture of a dog and a picture of a person look pretty much alike. The shape might be slightly different, or not. The colors may be different, or not. For a computer, all images only contain more or less pixels in different colors.

To be able to match images, a software has to find similarities and differences between the sample image and the images in the image database. These differences or similarities are then used to calculate a difference (distance) measure between the image searched for and each individual image in the image database.

This is never an exact process, except there are duplicate (identical) images in the database. The best one can get is a list of images that have a smaller distance to the original image than the rest of the images in the database.

IMatch always shows the best matches found for a given sample. It is up to the user to finally decide which images are identical or close enough to the actual sample image.

Although being not as good as a human in matching images, IMatch is much faster. On a current machine with 333 MHz IMatch is able to match a single image against a database holding about 20.000 images in only 3 seconds.

Using the results of such a query, a person should be able to find the »best« images much faster and with much less effort than doing this manually.


Creating a database for your images

See also: Adding images to your database , Updating images in a database

The first thing you have to do is to create an image database. This database holds the information required by IMatch to perform image queries.

IMatch databases store the image file location (path) and the color and texture information required by IMatch, but not the images themselves. This keeps the database size small and allows IMatch to handle large amounts of images (several 10 thousands) per database. The actual image is only required when the result set is displayed after a match operation. At this time, IMatch uses the image file location stored in the database to access and display the image.

When you use external storage media to store your images (like CD-ROM or DVD) you can create IMatch databases for each of these mediums. When you want to query a database for such an external medium, make sure that the right medium is inserted before you perform the match. Otherwise IMatch will not be able to display the images in the result set.

The standard file extension for IMatch databases is .imd, which stands for IMatch Database. Each IMatch database consists of two files. The main database file is <Filename>.imd, the actual data storage for the matching data is in a file named <Filename>.imi.
If you copy IMatch databases manually, make sure that you keep these two files together!

The maximum size of an IMatch database is virtually unlimited and depends only on how many images are added to the database. The current version of IMatch needs about 1300 bytes per image + some extra bytes for administrative purposes. An image database with 10.000 images needs about 13 MB of storage on your hard disk. Compared to the storage that is required by 10.000 images, this is quite fair.

To create a new database, follow these steps:

•	Switch to the [Database] Tab

•	Click on the Create new Database button

•	In the file selector dialog, enter a new file name for your new database and press OK. You can also select an existing database file to overwrite it.

After the database has been created successfully IMatch automatically loads the new database as the current database. The Stats area of the [Database] Tab shows that the database contains no images at the moment.

To add images to your database, switch to the [Scan] Tab and follow the directions in Adding images to your database.

Opening an existing database

With the Open button you can browse for an existing database to open. The »Last Recently Used« pull-down at the right side of the Open button contains the names of the last four opened databases. You can quickly reopen a database from there by just selecting the corresponding entry from the menu.

A note about IMatch databases and networks

IMatch stores the file name and location (folder) of each image in the database. When you move image files on your hard disk, IMatch will loose the link to the image file. This will not affect the matching operation itself, but will hinder IMatch to display the image in the result set. When you move images on your disks that are indexed by an IMatch database, make sure that you update the database file and also add the moved images to the database afterwards.

The same applies to accessing an IMatch database over the network. Since IMatch currently stores the full path of all images in the database, it probably will not be able to resolve these links when you access the images from a different machine.

As a workaround for this scenario you can create identical substitution drives on all machines that access the image database. Say, each machine has a SUBST (see the Windows Online Help for more information) that maps drive I: to the actual drive where the images are located. When you create the IMatch database, you use this drive to add the files to the database. This way, all machines that map drive I: to the same machine/drive will be able to see the thumbnails for the images.


Updating images in a database

See also: Creating a database for your images , Adding images to your database

When you delete images on your disks that are indexed by an IMatch database, these images become orphaned. Orphaned means in this context that the images are in the IMatch database but don't exist on the original storage media or location anymore.

Whenever you perform a query with IMatch and the result set contains physically deleted images, these images are marked as orphaned when displayed. IMatch checks every image of a result set to make sure that the image exists on the original storage media. If a image does not longer exist or cannot be accessed, IMatch treats the corresponding entry in the image database as orphaned.

To remove orphaned images, you can use the Update Database button on the [Database] Tab. When you press this button, IMatch scans the current database for orphaned images and removes them from the database. After the process has completed, all orphaned or otherwise inaccessible images are removed from the database and the database does not contain any references to inaccessible images.

•	This operation does not add new images or update modified images. It only deletes orphaned images from the database and updates images in the database that have changed on disk.

To add new images to a database use the [Scan] Tab.


Adding images to your database

See also: Creating a database for your images , Matching Images

After you have created a new database, or opened an existing database, you can immediately start to add images.

You can add selected images or add all images in a folder at once. Usually, you will add all images in a folder, recursively scanning all sub-folders of that folder.

To add images to the current database:

•	Switch to the [Scan] Tab

•	Click on Add Images when you want to select specific images to add to the database

•	Click on Add all images in a folder when you want to add all images in a folder

When you check the Act recursive on folders, IMatch will also include all images in the sub-folders of the selected folder.

IMatch will only read images with one of the supported file formats . All other files in the scanned folders are ignored during the scan.

When you press the Enable Display button, IMatch displays the images while they are added to the database. Enable this option only if you really want to see which image is currently processed since it slows down the add process considerably.

You can press Stop at any time to abort the current process. IMatch will finish with the current image and then abort the operation.

Drag and Drop

You can also drop images directly on to the [Scan] Tab to add them to the database. Select the images you want to add in the Windows Explorer and drag the selection over the IMatch application window when the [Scan] Tab is in front. When you release the mouse button, IMatch adds all images of the selection to the database.

Updating existing images or folders

When adding images, IMatch checks whether the image is already in the database and if it needs to be updated. When you add the same images or folders twice, IMatch will skip all images already in the database, as long as they have not been changed in the mean time.

When you add new images to a folder on your disk, you can simply re-scan that folder with IMatch. Only those images will be added to the image database that are not already in the database or that have changed since they were added the last time.

See also Updating images in a database for more information.

Handling Corrupt Images

Not all of the images out there are perfectly shaped and valid. From time to time, IMatch may encounter a corrupt image that it cannot handle.

If this happens, IMatch skips the file during the scan and reports the file on the [Scan] tab as ‘skipped’. After the scan has completed, IMatch displays a dialog containing the names of all skipped images.

From this dialog, you may copy, delete, view (open) or move the skipped images. The dialog is drag-and-drop enabled, you can drag the files from the dialog directly to your favorite imaging application, the windows recycle bin or any folder on your hard disk.

After you have added images to you database using the Scan operation, you can begin to match images. See Matching Images for more information on this subject.


Matching Images

See also: The IMatch Result Window , Creating a database for your images , Adding images to your database

The process of taking a sample image and match this image against all images contained in an image database it called an image query or matching operation. Image Matching is performed on the [File Match] Tab.

You can match one or more images by pressing the Match images button or match all files in a folder with the Match folder button. If you check the Act recursive on folders option, IMatch will automatically match the selected folder and all images in the subfolders of that folder.

You can also drop images directly on to the [File Match] Tab to match them against the database. Select the images you want to match in the Windows Explorer and drag the selection over the IMatch application window when the [File Match] Tab is in front. When you release the mouse button, IMatch matches all images of the selection with the database.

The Rematch button allows to you re-match the last selected images (or folder) with the current settings in the dialog. This is very useful when you try out different settings to find the optimal result for a specific kind of image.

If you match images that are already in the database, IMatch retrieves the required information directly from the image database instead of loading and processing the original image again. This saves a considerable amount of time during matching.

Controlling the query operation

The right side of the tab contains all controls that effect the match operation. Here you can adjust the parameters that the IMatch Engine uses when it queries the image database.

Match method

This is the method that IMatch uses to identify »similar« images. IMatch implements several methods for matching, for a variety of different requirements. Each method has it's strength and weaknesses and you'll need to try out which methods best fit for your kind of images.

Color Distance	This method matches images based on their color distribution in a quantized histogram. This method works good for all kind of images, but does not consider specific shapes

Scaled Color Distance	This method is basically the same as above, but is tuned to perform better for images that have been resized or rescaled

Weighted Shape	Shape is often a very important feature of an image. When you only look at the color distribution, an image of red circle on a black background and an image of a red box on a black background will be treated as similar.
The Shape Match feature of IMatch tries to identify specific shapes and shape distributions in an image and orders the result set based on the shape distance.
The Weighted Shape match method does not look after the color distribution of an image and hence treats similar shapes as equal, independent from the actual color of the shape.

Weighted Shape and Color	This match method looks after the shape and the color of an image to find similar images. This is usually the best method to try first.

CRC checksum	When you want to identify duplicate images in your database that are binary identical to a given sample (but possibly renamed or stored in another folder) you can use the CRC checksum match method.
This method is very quick and will find only truly identical images in your image database.

Filename	This method looks up all images with the same name as the original image. It is useful when you have many images with the same name that are stored in different folders and you want to clean up all duplicates.

When you are only looking for images that match in color to a give sample, use the Color Distance or Scaled Color Distance methods. These methods perform a ranking only by color, without putting much weight at the actual shape of an image.

To find images with a similar shape, use the Weighted Shape and Color method. This method usually produces the best results with respect to color and shape.

Max. Distance

The Max. Distance slider control allows you to limit the maximum »match distance« between the original image and the images considered as hits during the database query. IMatch measures the similarity between images as a percentage, ranging from 0% (identical) to 100% (quite different). The higher you set the value of the slider, the more images will be considered as matches.

Image dimensions

Per default, IMatch matches images regardless of their size compared to the size of the original image. If you only want to treat images as similar when the relative size difference is below a certain threshold, you should enable this option. If you set this option for example to 200%, IMatch will only consider images as possible matches that are at maximum twice as large as the original image.

Tip	This feature is very useful when you search for images that come from the same series. There is a good change that all of the images are about the same size, although they have different shapes or some variations in color.
When you use the image dimensions as an additional criteria, you will get far better results.

Limit the number of hits per file to

Depending of the setting of the Max. Distance option, IMatch may produce result sets with a large number of hits. With this option you can limit the maximum number of hits per file (when you match multiple files or all images in a folder) displayed in the result set. Usually, a value between 20 and 50 works best.

You can also limit the number of hits per file by setting the Max. Distance option to a smaller value.

IMatch automatically limits the number of images displayed in the result set to the number of thumbnails in the cache as defined on the [Options] tab.

Sort the Result Set by

This option allows you to specify the sort order for the images in the result set. You can sort the result set by distance (closest matches first), by folder, file name or a combination of these options.

Saving and restoring presets

You can save the current settings as a preset by pressing the [+] button near the Presets combo box. When you enter a new name, the settings are stored under that name. When you only press [+], the settings are stored under the name currently displayed.

To retrieve a stored preset later, just select it in the Preset combo box.

You can also delete presets with the [-} button. The Default preset cannot be deleted. When you try to delete it, IMatch will instead restore the factory settings for the Default preset.

See also: The IMatch Result Window , Tips & Tricks , Image Matching, not an exact science , A note about IMatch databases and networks


The IMatch Result Window

See also: Matching Images , Creating a database for your images , Adding images to your database

When IMatch has performed an image query, is displays the result set (all images that are considered similar to the original image) in the IMatch Result window.

The left side of the window contains a hierarchical view of the original images and the matches found. Each image is displayed with it's full name and location. A percentage bar displayed directly in front of each image indicates the match distance between the image and the original image, with respect to the Max. Distance setting. The more green you see in this bar, the better the match is (the closer this image is to the original).

On the right side of the result window IMatch displays thumbnails for all matching images found. The original image is surrounded by a red border. It is usually displayed at top left, since it has always a match distance of 0%. However, depending on the sort order you have chosen on the [File Match] Tab, the position may vary.

When you are finished with the current result set, you must close the result window to get back to the IMatch main window. The Result Window is closed automatically when you perform a Rematch by double-clicking on one of the thumbnails.

Thumbnail commands

When you right-click an thumbnail image, a context menu is displayed with the commands available for the selected image.

Open	This command opens the selected image(s) with the associated application for that file type (e.g. .JPG)

Open All	Opens all images of the current original with the associated application.
This option is only available when you click on the original image.

Copy	Copies the selected image to the Windows clipboard

Copy Name	Copies the name and path of the current image to the Windows clipboard

Copy Files to	Copies the selected images to a different folder on your hard disk.

Move Files to...	Moves the selected images to a different location on your hard disk

Delete Files...	Deletes all selected images into the Windows recycle bin

Rematch selected...	Performs a match operation with the current settings and the current selected image(s). This is a very powerful feature, allowing you to »drill-down« into your image libraries as you discover interesting images.

Refresh Display...	When you manipulate one or more of the displayed images in an external program (for example, open it from IMatch and then delete it), IMatch will not display the file as deleted in the Thumbnail Viewer.
By pressing <F5> or choosing this menu item, you can refresh the Thumbnail View to display the changes.

These commands also appear in the context menu of the hierarchical view and are accessible via the toolbar.

Double-Clicking

Double-clicking the mouse on one of the images executes the default action which is defined on the [Options] tab. You can specify whether a double-click should Open the selected images or run a Rematch on the selected images.

The Toolbar

The toolbar allows you to quickly access all file and match commands:

Drag and Drop

The IMatch Result Window is fully drag and drop enabled. This feature allows you to:

•	Drag the currently selected files to your favorite imaging application to open them

•	Drag files to a folder on your desktop or a Windows explorer window. This is very handy when you perform cleanup or reorganize your images using IMatch.
If you press <Shift> during the drag, the files are moved, else they are copied.

•	Drag files to the Windows recycle bin to delete them.

The Status Bar

The status bar at the bottom of the Result Window displays information about the current image when you move the mouse over the image display.

It shows the file name, the image dimensions, the size of the image on your hard disk and the [matching distance].


IMatch Options

On this Tab you can set some options that influence the working of IMatch.

Automatically reload last database on startup

When you check this option, IMatch will load the last active database automatically the next time it is started.

Thumbnail Preview

This option allows you to specify the size of the thumbnail images displayed in the IMatch Result Window . This option only takes effect when you restart IMatch.

Thumb cache entries

IMatch uses system memory (RAM) to cache thumbnails for the images displayed in the Result Window. When you browse the result set or perform Rematch operations, IMatch often can fetch a thumbnail from it's internal cache instead of reading it from the disk. Since it is much faster to reuse an already existing thumbnail instead of loading the image file from disk, this allows for a much faster operation.

Depending on the amount of memory built into your computer and your preferences, you can adjust the number of thumbnails that are cached. The higher the number of cached thumbnails, the more memory will be used. A Thumb cache entries value between 100 and 400 has proven to provide the best overall effect.

Hide Originals without matches

If you check this option, IMatch will only display original images in the Result Window that actually have one or more matches. All originals without matches will be hidden.

This option comes handy if you use very strict match settings or match a large number of files at the same time. You will see only original images in the hierarchical view that actually have one or more hits.

Double-Click in Image View performs

Here you can specify the default action for a mouse double-click in the Thumbnail View.


Skipped Files

This dialog shows you the files that have been skipped during the Scan  process.

During the scan process, IMatch skips all files which cannot be read or which are corrupted. These files are then presented in this dialog after the scan has completed.

You may use this dialog to open, delete, move or copy the invalid images files. You can also use drag and drop to drag these files on to your favorite imaging application, the Windows recycle bin or a folder on your hard disk.

For more information, see Handling corrupt images


About IMatch

This tab displays some information about IMatch. Here you find the version of IMatch and the IMatch Engine used, together with the Copyright information.

Registering IMatch

When you use an unregistered copy of IMatch for evaluation purposed, this dialog also contains the Register button which allows you to enter the registration information.

Please enter the registration information exactly as received, the registration process is case-sensitive. After a click on the Register button in the dialog, IMatch is set into the registered mode and all »Nag Screens« will disappear automatically.

For more information about registering IMatch look at The Shareware Principle and Registration of IMatch


Technical Information

Hardware Requirements

•	PC with at least a 486 or better processor

•	64 MB RAM or more

•	Windows 95 with Service Pack 1 installed or

•	Windows NT 4.x with Service Pack 3 installed

•	Mouse or compatible pointing device

•	Graphic adapter with at least 32K colors (High-Color or True-Color preferred). Graphic cards with 256 or less are not supported.

Supported File Formats

IMatch currently supports the following file formats:

•	JPEG compliant (*.jpg, *.jpeg)

•	Truevision Targa (*.tga)

•	Tagged Image File Format (*.tif)

•	Macintosh PICT (*.pct)

•	Windows or OS/2 Bitmap (*.bmp)


Tips & Tricks

How to find duplicate images?

To find duplicate images, even if the have been renamed, resized or converted into another file format, perform a match with the Scaled Color Difference or Weighted Shape and Color methods. Sort the result set by Distance, Folder, Filename.

How to find only truly identical images?

To find binary identical images (duplicates) use the CRC checksum method .Sort the result set by Distance, Folder, Filename.

How to find the best matches?

To find the best possible matches, you should start with the Weighted Distance and Color match method. This method has proven to be the most reliable for the majority of images.

When you only want to find images that match in color to a given sample, you can use the Color Distance or Scaled Color Distance methods. These methods consider images as similar when the have the same kind of color distribution.

Generally speaking, depending on the kind of images you store in your database, you should try out different settings to see what fits best. You can save the best settings for your requirements as presets and reload them at any time to perform more queries.

Image Series

When you try to find all images from a series and that series contains images with some variation in color and shape, you should use the ‘Consider image dimensions’ option with about 5%-20%. There is often a good chance that images from a series have approximately the same size and this setting will limit the difference in size to a amount of 5-20 percent from the original image.

How to find images with a specific shape?

You can create sample images for a variety of shapes with a paint program of your choice. For example, you may draw a black circle in front of a blue background, save this image as a file on your disk and use it as the original image for IMatch queries.

You get the best results for the Shape match methods when the original image has a high contrast or a clean setup, e.g. a red car in front of a blue sky. The shape match algorithm in IMatch performs very well on these kind of images.

If the original image is very »noisy«, with many colors and many details, the shape match algorithm may not find all similar matches or may find some totally unrelated (from a humans point of view) matches.

This behavior is by design. Upcoming versions of IMatch will probably include better algorithms to deal with much more detail in the original image.


Database Name

This edit field shows the name of the current open database.


Open Database

Press this button to open an existing database.


Last recently used databases

This menu contains the names of the 4 last recently used databases. Just click on one of the entries to reopen.


Update Database

Use this button to update the current database. The update operation will remove all orphaned (deleted) images from the database and will result in a smaller database file.


Create a new database

Press this button to create a new database file.


Add images

Press this button to add selected images to your database


Add all images in a folder

This button allows you to add all images in a folder. You can also add all images recursively when you enable the »Act recursive on folders« check box.


Act recursive on folders

Enable this check box if you want to scan also subfolders when you add images


Image Preview

This space displays the images while they are added to the database


Enable Display

Click this button to enable the image preview.


Stop

This button aborts the current operation


Match images

Match one or more selected images


Match folder

Match all files in a folder


Rematch

Rematch the current set of files with the actual settings


Presets

List of available presets. Select an entry from this list to load the associated settings


Add Preset

Saves the current settings as a preset


Delete Preset

Deletes the current preset


Match Method

List of available match methods


Match Threshold

Use this control to define the maximum match distance


Image dimensions

Controls whether IMatch considers the size of the images


Size

Controls the maximum size difference between the original image and the images considered as hits


Number of hits

Limits the number of hits per file


Maximum hits

Specifies the maximum number of hits per original image


Sorting

Specifies the sort order for the result set


Auto-Reload

Enable this option when you want IMatch to reload the last used database at startup


Thumbnail size

Size in pixels of the thumbnails displayed in the Result Window


Thumbnail size

Size in pixels of the thumbnails displayed in the Result Window


Thumbnail size

Size in pixels of the thumbnails displayed in the Result Window


Thumbnail Cache

Controls the number of entries in the thumbnail cache


Help

Displays the Online Help System


Register

This button brings up the register dialog. Here you can enter your personal licensing information


Type Caption for New Topic Right Here
Delete Image

This button deletes the selected image files


Type Caption for New Topic Right Here
Move images

This button moves the selected images files to a new location on your hard disks


Type Caption for New Topic Right Here
Open

Opens the selected images files with the associated application


Type Caption for New Topic Right Here
Skipped File List

This list contains all the skipped files


Recursive Matching

Check this option if you also want to match subfolders recursively


With Matches Only

Only show original images in Result Window that have at least one match. All other originals are hidden in the hierarchical view.


Double-Click

Defines the double-click action for the Result Window


Double-Click

Defines the double-click action for the Result Window