home *** CD-ROM | disk | FTP | other *** search
Text File | 1992-12-11 | 41.7 KB | 1,026 lines |
-
-
-
-
-
-
-
-
- I M G F U N . T X T
-
- C O N T E N T S
-
-
-
- 1. Introduction. . . . . . . . . . . . . . . . . . . . . . .1
-
- 1.1 ImgFun Package . . . . . . . . . . . . . . . . 1
- 1.2 Packing lists. . . . . . . . . . . . . . . . . 1
-
- 2. ASP Ombudsman . . . . . . . . . . . . . . . . . . . . . .2
-
-
- 3. System Requirement. . . . . . . . . . . . . . . . . . . .3
-
- 3.1 Display mode . . . . . . . . . . . . . . . . . 3
- 3.2 VESA support . . . . . . . . . . . . . . . . . 3
- 3.3 SVGA support . . . . . . . . . . . . . . . . . 4
-
- 4. Computer Images . . . . . . . . . . . . . . . . . . . . .6
-
- 4.1 Gray Level Images. . . . . . . . . . . . . . . 6
- 4.2 Color Mapped Images. . . . . . . . . . . . . . 6
- 4.3 True Color Images. . . . . . . . . . . . . . . 7
-
- 5. What's ImgFun for?. . . . . . . . . . . . . . . . . . . .8
-
- 5.1 ImgFun under Windows and PaintBrush. . . . . . 8
-
- 6. General Operations. . . . . . . . . . . . . . . . . . . 10
-
- 6.1 How to start ImgFun. . . . . . . . . . . . . .10
- 6.2 Main menu functions. . . . . . . . . . . . . .10
- 6.3 The on line help system. . . . . . . . . . . .11
- 6.4 Fast Start . . . . . . . . . . . . . . . . . .11
-
- 7. Image Formats . . . . . . . . . . . . . . . . . . . . . 13
-
- 7.1 GIF. . . . . . . . . . . . . . . . . . . . . .13
- 7.2 PCX. . . . . . . . . . . . . . . . . . . . . .13
- 7.3 BMP. . . . . . . . . . . . . . . . . . . . . .13
- 7.4 JPEG (*.jpg) Compression and Decompression .14
- 7.5 Other Formats. . . . . . . . . . . . . . . . .16
-
- 8. Function Usage: . . . . . . . . . . . . . . . . . . . . 17
-
- 8.1 File:. . . . . . . . . . . . . . . . . . . . .17
- 8.1.1 Load: Load an image to work. . . . . . 17
- 8.1.2 View: View an image file.. . . . . . . 17
- 8.1.3 Save: Save the loaded image 1. . . . . 17
- 8.1.4 Quit: Quit ImgFun. . . . . . . . . . . 17
-
-
-
-
-
-
- 8.2 Adjust:. . . . . . . . . . . . . . . . . . . .17
- 8.2.1 Brighten: Brighten the loaded image. . 17
- 8.2.2 Darken : Darken the loaded image. . . 17
- 8.2.3 Contrast:. . . . . . . . . . . . . . . 17
- 8.2.4 cOlor :. . . . . . . . . . . . . . . 17
- 8.3 Set: . . . . . . . . . . . . . . . . . . . . .17
- 8.3.1 Background: Choose a background color. 17
- 8.3.2 Cut area :. . . . . . . . . . . . . . 17
- 8.3.3 Directions:. . . . . . . . . . . . . . 17
- 8.3.4 Threshold : View a binary map. . . . . 17
- 8.4 Transform: . . . . . . . . . . . . . . . . . .17
- 8.4.1 Rescale :. . . . . . . . . . . . . . 17
- 8.4.2 Smooth:. . . . . . . . . . . . . . . . 18
- 8.4.3 shArpen: . . . . . . . . . . . . . . . 18
- 8.4.4 rOtate:. . . . . . . . . . . . . . . . 18
- 8.5 Options: . . . . . . . . . . . . . . . . . . .18
- 8.5.1 Display : . . . . . . . . . . . . . . 18
- 8.5.2 card : . . . . . . . . . . . . . . 18
- 8.5.3 direcTory: . . . . . . . . . . . . . . 18
- 8.5.4 Dither : . . . . . . . . . . . . . . 18
- 8.6 Utility: . . . . . . . . . . . . . . . . . . .18
- 8.6.1 Compress : JPEG compression . . . . . 18
- 8.6.2 cOnvert :. . . . . . . . . . . . . . 18
- 8.6.3 sLide show: a manual slide show. . . . 18
- 8.7 Undo and Update: . . . . . . . . . . . . . . .18
- 8.8 Swap (F3) :. . . . . . . . . . . . . . . . . .19
- 8.9 DOS (F6) :Shell out to DOS. . . . . . . . . .19
- 8.10 Gray (F7) : . . . . . . . . . . . . . . . . .19
-
-
-
- ImgFun.txt Speedy Software page 1
-
-
-
-
- 1. Introduction
-
- 1.1 ImgFun Package
-
- ImgFun is a powerful image compression and enhancement
- program for computer images. ImgFun is designed to let you
- regain the tremendous amount of disk space occupied by GIF like
- images in your system and explore the pleasure of viewing
- images in the awesome 256-color SVGA modes.
-
- ImgFun is developed by Speedy Software and distributed
- as shareware. For shareware and registration, please read
- register.txt. Once again, for supporting affordable quality
- software, PLEASE REGISTER!!!
-
- 1.2 Packing lists
-
- IFSE100.exe : A self extracting file made by the Lha213
- package which is copyrighted by Haruyasu Yoshizaka contains
- the following files:
-
-
- readme.txt A short compilation of important information
- ImgFun.exe The program itself
- ImgFun.hlp The help file
- ImgFun.pif PIF for Windows
- ImgFun.txt This file
- register.txt Registration and development information
- order.frm an easy order form to register
-
- If you are missing one or more of these files, contact the
- author at one of the addresses listed at the end of this
- document.
-
- For installation, just copy all files to a proper
- directory of your hard disk.
-
- Please do read register.txt, it contains important
- information about the future development and planning of ImgFun.
-
- Some utilities might be included from Speedy Software.
-
-
-
-
- ImgFun.txt Speedy Software page 2
-
-
-
-
- 2. ASP Ombudsman
-
- This program is produced by a member of the Association
- of Shareware Professionals (ASP). ASP wants to make sure that
- the shareware principle works for you. If you are unable to
- resolve a shareware-related problem with an ASP member by
- contacting the member directly, ASP may be able to help. The
- ASP Ombudsman can help you resolve a dispute or problem with
- an ASP member, but does not provide technical support for
- members' products. Please write to the ASP Ombudsman at 545
- Grover Road, Muskegon, MI 49442 or send a Compuserve message
- via easyplex to ASP Ombudsman 70007,3536
-
-
-
-
- ImgFun.txt Speedy Software page 3
-
-
-
-
- 3. System Requirement
-
- A lot efforts have been made to make ImgFun as lean and
- fast as possible.
-
- [1] 286 or better PC with DOS 2.0 or above
- [2] 300 to 450K of free memory under DOS, no extended or
- expanded memory needed. Some of the memory is dynamically
- allocated. For the viewer, you need at least 300K.
- [3] VGA or SVGA display system. See "SVGA support" for SVGA
- support list.
- [4] Hard disk space for loading and processing images. One
- mega bytes or above free space is required. If you use
- ImgFun as a viewer only, no hard disk is required.
-
- For the bulkiness of image data and the tremendous computing
- load for processing images, a 386, or 486 computer with 2
- mega bytes of free disk space is recommended. ImgFun uses
- disk files for loading images up to 1024 by 1024, thus a
- disk cache like the smartdrv in DOS 5.0 or Windows 3.0 & 3.1
- will help ImgFun a lot and is strongly recommended.
-
-
- 3.1 Display mode
-
-
- ImgFun uses 256-color mode in the following
- resolutions for displaying images:
-
- 0. 300 x 200 standard VGA mode
- 1. 640 x 400 SVGA available for most cards with 256 KBytes
- 2. 640 x 480 SVGA needs 512 KBytes on board
- 3. 800 x 600 SVGA needs 512 KBytes on board
- 4.1024 x 768 SVGA needs 1024 KBytes on board
-
-
- 3.2 VESA support
-
- ImgFun also supports VESA (Video Electronics
- Standards Association) drivers with 64K window size starting
- at address A000h.
-
- In the auto-detection mode,ImgFun will try to identify
- your VGA card and determine the SVGA modes available. When
- your VGA card can not be identified, ImgFun will try to test
- if a valid VESA driver is present, if so the VESA driver will
- be used. If no valid SVGA chip and VESA driver available,
- ImgFun will use the standard 320x200 mode for displaying
- images.
-
-
-
-
- ImgFun.txt Speedy Software page 4
-
-
- WARNING: NOT ALL VESA DRIVERS ARE SUPPORTED. YOU HAVE TO TEST
- YOUR VESA CARD FIRST!!!!
-
- VESA drivers are usually in one of the VGA utility disks
- which are included in most VGA card packages or built in the VGA
- cards. Please consult your VGA card manual for installation of
- the VESA driver. Notice that not all VESA drivers are
- accepted by ImgFun. Only those detected and verified by ImgFun
- will be used.
-
- 3.3 SVGA support
-
- The following SVGA chips are under support in ImgFun:
-
- The highest resolution available is listed.
-
- [1] Trident Series: Everex VGA
-
- 8800: up to 640 x 480
- 8900, 9000 or newer: up to 1024 x 768
-
- [2] Tseng's Lab:
-
- ET3000: up to 800 x 600
- ET4000: up to 1024 x 768
-
- [3] Paradise cards or Western Digitals chip sets:
-
- WD90C00, WD90C10: up to 640 x 480
- WD90C11, WD90C30 or newer: up to 800 x 600
-
- [4] ATI Technologies:
-
- 18800, 28800 or newer : up to 800 x 600
-
- [5] Video 7, Headlands Technology:
-
- V7VGA series: up to 800 x 600
-
-
- [6] Chips and Technologies: Boca VGA
-
- 82c451: 640 x 400
- 82c452: up to 640 x 480
- 82c453: up to 800 x 600
-
- [7] Genoa Systems:
-
- up to 800 x 600
-
- A new change has been made in version 1.0. A -s switch is
- added for the standard 320x200x256 VGA mode. A new function,
-
-
-
- ImgFun.txt Speedy Software page 5
-
-
- card, is added to the Options menu. Now users can choose auto
- detection or manual setting of the display driver.
-
- Usually VGA chip manufactures maintain backward
- compatibility with their older chips when delivering new
- VGA chips. In most cases, your VGA card from the above chip
- vendors will be recognized by ImgFun.
-
- If problems are encountered for the SVGA modes, please
- contact the author.
-
-
-
-
- ImgFun.txt Speedy Software page 6
-
-
-
-
- 4. Computer Images
-
-
- ImgFun operates on computer images, so first a
- short explanation of what computer images are and how ImgFun
- works with these images.
-
- For our purposes, an image is a data set that describes
- the reflectance of a 2- dimensional surface such as a photograph.
- In particular, an image is a 2- dimensional array of "pixels",
- each of which contains data for the small rectangular area of
- the image it represents. Thus a pixel in an image w wide by h
- height is addressed by 2-dimensional coordinate (x,y) for x
- ranges from 0 to w-1 and y ranges from 0 to h-1. Usually the X
- direction is left to right and the Y direction is top down. This
- is the native format of ImgFun. Formats storing images in
- other directions will be converted into this practice. The
- value of each pixel is interpreted differently depending on
- the type of the computer image. There are three classes of
- computer images as follows:
-
-
- 4.1 Gray Level Images
-
- Gray level images represent images by storing the
- intensity of light for each pixel on a scale usually more than
- just on/off. Typically, a gray level image will allow 64 to 256
- shades of gray at each pixel. Very high quality renderings of
- black and white photographs can be stored in this way. In
- ImgFun, gray levels of images range from 0 to 255 with
- 0=Black and 255=White. Some times the gray level might be
- referred as the luminance( better to remember 255 is white). No
- color information is stored in the gray level images.
-
- 4.2 Color Mapped Images
-
- From color theory, any color can be derived from mixtures
- of 3 principle colors with proper proportions. Usually, red,
- green and blue are used as the three principle colors in
- personal computers. Each principle component requires 5 to 8 bits
- for most computer images.
-
- Color mapped images are the ones most common on
- personal computers. Each pixel in an image is represented by
- a number (called an index) that is used to look up the
- pixel's actual colors in a table (called the palette). These
- images are popular because they can be very colorful, yet take
- up less memory than full-color images (described next).
-
- The size of the color palette varies among formats, but
-
-
-
- ImgFun.txt Speedy Software page 7
-
-
- is typically 16 to 256. These are the major type of images ImgFun
- is designed to work with. In concept, you can treat a gray
- level image as a color mapped image with a pre-defined
- palette such that all the entries have equal values in red,
- green and blue components from 0 to 255.
-
-
- 4.3 True Color Images
-
- True color images are the highest quality representation, and
- the largest files as well. Each pixel contains the complete
- color information for that pixel, usually expressed as the
- intensity of the red, green, and blue color components of the
- light at that location. For 24 bit rgb images, each pixel is
- represented by one byte in red, green and blue component
- respectively. Some images use 5 bit per principle to result in
- a pixel represented by 2 bytes( 16 bit) or so called
- 32768-color images. These 16 bit images are emerging in the PC
- world from support of new display cards available. The extra
- bit in 16 bit images can be used for other purposes like cut and
- paste.
-
-
-
-
- ImgFun.txt Speedy Software page 8
-
-
-
-
- 5. What's ImgFun for?
-
- ImgFun deals with gray and color mapped images in Ver. 1.00
- and the next major update version will deal with true color
- images directly. ImgFun does the following jobs for users:
-
- [1] display:
-
- Let user view images. Show loaded images with instant
- zooming and scrolling. Reverse and mirror images instantly.
- Also a manual slide show is implemented.
-
- [2] enhancement:
-
- Alter colors of images. Process images for visual pleasure.
-
- [3] format conversion:
-
- Convert between any two formats supported.
-
- [4] compression:
-
- Compress color mapped images and gray level
- images by JPEG compression. Images are reduced to a
- fraction of the original size for reducing the heavy
- burden of keeping a large archive of image files.
-
-
- 5.1 ImgFun under Windows and PaintBrush
-
-
- You can run ImgFun under MicroSoft Windows 3.0 or 3.1.
- But please use the FULL SCREEN MODE ONLY and press Alt-Tab
- to switch from ImgFun to Windows. In Windows, you can click the
- icon of ImgFun to switch from Windows to ImgFun.
-
- DON'T RUN IMGFUN IN A WINDOW UNDER WINDOWS. This might
- produce unpredictable results if other Windows application and
- ImgFun contend for the video memory.
-
- If you are using Windows 3.1, there's a built in print out
- function in PaintBrush, which can be located in the accessory
- group. PaintBrush accepts PCX and BMP formats. Both are supported
- by ImgFun. To import images to PaintBrush, you just save or
- convert images into PCX, or BMP images and use the open function
- in PaintBrush to load images. In PaintBrush, you can also write
- texts on the image with various fonts and do cut and paste
- of images.
-
- The print out quality of PaintBrush is quite good,
-
-
-
- ImgFun.txt Speedy Software page 9
-
-
- especially on laser printers. A print out module is under
- development in Speedy Software. This print out module will
- let users choose different algorithms for printing images, and
- the current module will be available as a bundled bonus for
- registered users.
-
-
-
-
-
- ImgFun.txt Speedy Software page 10
-
-
-
-
- 6. General Operations
-
- 6.1 How to start ImgFun
-
- Type "ImgFun" or "ImgFun -s", under the system command line
- with ImgFun.exe in the current directory to start ImgFun, or
- use ImgFun.PIF to start ImgFun under Windows. Then you will
- enter the main menu in the menu mode. A pull down menu (the
- main menu), a status box and a function key bar are displayed
- in the menu mode. Type in the capitalized letters or use
- arrow keys for selecting functions in the main menu. An
- on line help system is implemented for easy use, also a
- good source of information. The auto-detection mode is
- default and backward compatible with previous test
- versions. If you have problems in starting ImgFun by the
- auto-detection function, even after you installed a VESA
- driver, then you should start ImgFun with the standard mode by
- "ImgFun -s" in the command line. Now the standard mode will
- use the 320x200x256 VGA mode only, unless the user has
- changed the display driver by the function Options,
- Display, card.
-
- WARNING:ONLY USE MANUAL SETTING WHEN THE AUTO DETECTION FUNCTION
- FAILS AND YOU ARE SURE YOU HAVE A VGA CARD WITH A NEWER CHIP OF
- SOME VGA CHIP VENDOR LISTED. THE DISPLAY CARD FUNCTION IS
- PROVIDED FOR THOSE NEW CHIPS FROM LISTED VGA CHIP VENDORS.
- USUALLY NEW CHIPS FROM THE SAME VENDOR MAINTAIN BACKWARD
- COMPATIBILITY IN THE MODE SETTING AND PAGING MECHANISM WITH OLDER
- CHIPS, BUT MIGHT NOT BE PROPERLY IDENTIFIED BY IMGFUN.
-
-
- 6.2 Main menu functions
-
- File : View, Load, Save, Quit
- Adjust : Brighten, Darken, cOntrast, Color
- Set : Background, Cut area, Directions, Threshold
- Transform : Rescale, Smooth, shArpen, rOtate
- Options : Display, direcTory, dIther
- Utility : Compress, cOvert, sLide show
-
- Function keys:
-
- F1:HELP, F2:UNDO, F3:SWAP, F4:UPDATE, F5:SHOW, F6:DOS, F7:GRAY
-
- And function key F10 is used to show
- registration information.
-
- Some of the functions might require selections from lists
- or input parameters to do the job. For the list selection, you
- can use Up, Down, Page Up and Page Down to scroll for the
-
-
-
- ImgFun.txt Speedy Software page 11
-
-
- item or type in the name of the item, as you type in the
- letters, ImgFun will try to match the closest item for fast
- access.
-
-
- For input dialogues, you can always use ESC to abort and
- F1 for help.
-
- During the operation of ImgFun, if something went wrong,
- ImgFun will report error messages. Simply follow the
- instructions to continue to work. The most common errors are
- not enough memory or disk space, and an invalid image format
- encountered.
-
- 6.3 The on line help system
-
- For the help system (activated by pressing F1 in the menu
- mode), you can use Page Up and Page Down to scroll, Esc to
- abort and Space bar for the topic selection list.
-
- 6.4 Fast Start
-
- ImgFun works on images stored in some pre-defined
- formats. An image format specifies how information is stored
- for the image and eases the job of exchanging images in
- different applications. ImgFun supports several formats
- which will be explained in the next section. Files with
- corresponding format extensions will be treated as images
- saved in corresponding formats.
-
-
- For viewing images, use the File, View function. A manual
- slide show can be performed by storing image file names ( do
- specify full paths for ImgFun to locate image files) in a text
- file by one file name a line from the beginning of each line.
- Simply use the Utility ,sLide show for your slide show
- entertainment.
-
- A more powerful viewing program for the pleasure of
- seeing computer images is provided for loaded images. To load an
- image, please use the File, Load function. Up to two images
- can be loaded at a time. Information about the loaded image 1
- and loaded image 2 is reflected in the status box. Loaded
- files will be stored on the current directory. After ImgFun is
- started only the help file ImgFun.hlp is needed. You must
- specify the help file directory in Options, direcTory, Help to
- use the help system, if ImgFun is started in a different
- directory other than the directory which ImgFun.hlp resides.
- If you use a ram disk to start ImgFun, make sure you have
- enough space for loading big files. A disk caching program
- is strongly recommended for fast response. According to
- experience, a ram drive will be redundant , if the
-
-
-
- ImgFun.txt Speedy Software page 12
-
-
- smartdrv from Windows 3.1 is loaded. Smartdrv does a very
- good job in disk caching when working with ImgFun.
-
- After an image is loaded, you can use the Show function
- by pressing F5. In the show mode, the loaded image 1 is displayed
- in the screen by 256-color VGA, or SVGA modes. Press Page Up
- and Page Down for instant zooming up to four times in width
- and height. Use the arrow keys to scroll and the '+' and '-'
- keys to increase or decrease the scroll step size. A lot of
- tricks can be played in the Adjust and Set functions. You'll
- get instant response by trying these functions. A built in
- undo and update mechanism let you experiment on the loaded image
- 1.
-
- One VERY VERY IMPORTANT thing to remember is that
- before switching the display mode by Options, Display, mode
- MAKE SURE YOUR MONITOR CAN STAND THE HIGH RESOLUTION MODE you
- want to try, OTHERWISE YOU MIGHT BURN YOUR MONITOR'S TUBE,
- ESPECIALLY THE KILLER MODE OF MONITORS, 1024x768.
-
- If problems are encountered for some SVGA modes, please
- contact the author for technical support. I have tried my best
- to include as many drivers as I could for the wild supper VGA
- cards.
-
- A set of functions that might need some patience to wait
- is grouped in the Transform menu. These functions will
- produce another image file from the loaded image 1.
-
- For image compression and format conversions, try
- Utility, Compress and cOnvert functions.
-
- Tremendous efforts are spent to make the compression and
- decompression as fast as possible by not eating too much
- precious memory under DOS.
-
- The compression is designed for continuous tone color
- mapped images and gray level images. Color mapped images with
- fewer than 32 colors and gray level images with fewer than 16
- colors will not be accepted by ImgFun for compression. Just save
- or convert these images in the GIF format which should
- yields good compression results for these images.
-
- For the compression level required by JPEG compression, try
- 3 to 10 for color mapped images and higher for gray level images.
- The best result might need some experiments depending upon your
- eyes and the image contents.
-
-
-
-
-
- ImgFun.txt Speedy Software page 13
-
-
-
-
- 7. Image Formats
-
- ImgFun Ver. 1.00 supports the following formats:
-
- 7.1 GIF
-
- This is CompuServe's Graphical Interchange Format. GIF
- images are widely used in networks like CompuServe and local
- BBSes. GIF format stores color mapped images using 12 bit LZW
- compression. In the world of personal computers, color mapped
- systems still dominate. GIF offers good compression for storing
- color mapped images and is supported by a lot software vendors.
-
- There are 2 versions of GIF images, 87a and 89a.
- 89a is a backward compatible extension of 87a.
-
- ImgFun reads in both versions but ignores features in
- 89a. For multiple images in a single GIF file, only the first
- image is retrieved. ImgFun always writes out GIF images in 87a.
-
- GIF format is recommended for storing images frequently used,
- for example in a slide show and images waiting for processing.
- Since the coding and decoding are fairly fast.
-
- 7.2 PCX
-
- This is ZSoft's Paint Brush's native format. PCX is probably
- the first image format gained wide support from
- different applications. PCX uses 8 bit run length encode for
- storing gray and color mapped images. The latest version supports
- 24 bit true color images.
-
- ImgFun reads in PCX images with palette information.
- Images stored in the latest true color format will not be
- accepted by ImgFun.
-
- ImgFun always writes PCX images with palette information.
- The next major upgrade version of ImgFun will support 24 bit
- true color images in PCX format.
-
- PCX format is recommended for images requiring fast
- access, since the decoding and coding are blindly fast.
- But the compression is in general inferior to the GIF format.
-
- 7.3 BMP
-
- BMP is the device independent bit map format from
- MicroSoft.
-
- BMP can store gray, color mapped and true color images. For
-
-
-
- ImgFun.txt Speedy Software page 14
-
-
- the popularity of MS Windows 3.0 and 3.1, BMP is becoming
- another standard format in PC applications.
-
- Old BMP files before Windows 3.0 are not accepted by
- ImgFun. As mentioned before, true color images are left in
- the next major upgrade version.
-
- ImgFun reads and writes BMP images in uncompressed form,
- since BMP format is designed to be loaded as fast as possible
- under Windows.
-
- BMP format is recommended for wall papers in Windows
- and exchanges for Windows programs. No compression is used for
- the BMP format. Thus you can use the BMP format as the
- comparison basis for compression mechanisms used by other image
- formats.
-
-
- 7.4 JPEG (*.jpg) Compression and Decompression
-
- JPEG stands for Joint Photo Experts Group. JPEG is an
- image compression mechanism by 8 by 8 DCT transform coding and
- entropy coding.
-
- JPEG is designed to offer varied level compression of
- continuous tone true color and gray level images by throwing away
- information barely noticeable by the human visual system.
- There are several stages involved in the JPEG mechanism. For
- users not interested in the technical stuff can skip the
- following materials and go to the end of this section.
-
- First, the true color image is converted into the Y, U,
- V space. The Y component represents the luminance, i.e., the
- gray level of the image. U,V components store information about
- the chrominance, i.e., the colors. For the human visual
- system, the luminance is more important than the chrominance.
- Thus the U, V components are sub-sampled for reducing the
- amount of data. Usually, only half samples in the horizontal
- direction and half lines in the vertical direction are
- retained. This reduces the U, and also the V components to only
- a quarter of the Y components. Comparing with RGB data, only
- half amount of storage is required for this sub-sampling in
- YUV space. For gray level images, the value of each pixel
- is just the luminance, i.e., the Y component of the
- pixel. Thus no compression is obtained in this stage for gray
- level images.
-
- ImgFun converts color mapped images into true color images
- internally, then converts true color images into the Y, U, V
- sub-sampled space. The palette information is tagged in the
- header of a JPEG compressed image for decoding.
-
-
-
-
- ImgFun.txt Speedy Software page 15
-
-
- In the next stage, the data is divided into blocks such that
- each block contains 8 pixel by 8 pixel in Y,U and V components
- respectively. Last blocks in each row and column are padded, if
- necessary, to form 8 by 8 blocks.
-
- Each block is fed into an 8 by 8 two dimensional discrete
- cosine transform to obtain 64 coefficients representing the
- block. Then the coefficients are quantized by predefined
- tables. Different tables are used for the luminance and
- chrominance components. After quantization, information about
- the block is packed in the lower frequency coefficients. A
- lot coefficients will become zero and all coefficients are
- represented by integers. By adjusting the quantization tables,
- we can gain various results. This is where the information is
- thrown away.
-
-
- Then an efficient run length coding of zero coefficients
- and varied length coding of non-zero coefficients by
- Huffman coding (or arithmetic coding which is not supported in
- ImgFun) are applied to yield a shrink down result.
-
- The decoding process reverses the above stages. But users
- are expecting color mapped images as decoded results. ImgFun uses
- the tagged palette to map each pixel into the palette.
- According to experience, this process of remapping takes
- about a third to more than half of the total decoding
- process. This is why it's much slower in the decompression
- of color mapped images than the compression. Also the
- remapping process loses information. This is the price paid
- for the color mapped display system.
-
- ImgFun only accepts JPEG images with Y,U,V 2:1:1 sub sampling
- in horizontal and vertical directions with one interleaved
- scan. A non-interleaved format stores the luminance
- and chrominance components separately. This makes it
- impossible for a fast efficient one pass decoding process
- without huge amount of memory (bytes needed :three times the
- width times the height of the image). Thus these images are
- not supported. Although, JPEG document does not specify the
- color space, the Y, U, V space is becoming the standard.
- For JPEG images without palette information, a uniform
- palette is used for decompressing the JPEG image into a color
- mapped image. The result may not be satisfied. This problem
- is left in the next version. The major drawback of JPEG is
- that the decoded result is a true color image which is hard
- to appreciate in the PC world. ImgFun attacks this problem by
- tagging the palette and remapping the true color image into a
- color mapped image in the decoding process.
-
- For a color mapped GIF image, the JPEG compressed image
- usually have a compression ratio 3 to 10 depending upon
-
-
-
- ImgFun.txt Speedy Software page 16
-
-
- compression level specified.
-
- For a gray level GIF image, a compression ratio above 10
- can be achieved without much visual distortion. ImgFun offers
- the function to view compressed JPEG images without decoding
- into disk files. This will help a lot when viewing JPEG
- images stored in a floppy disk, especially for gray level
- images which are decoded quite fast under ImgFun.
-
- ImgFun reads in base line JPEG files complying with the
- revision 8 and revision 9 drafts with restrictions mentioned
- and always writes out JPEG images that comply with the revision
- 9 except that an application tag is used for the palette and
- some private information which should be ignored by other
- software.
-
- Users are recommended to store final images (images don't
- need processing any more and are used mainly for viewing
- and printing from the archive) by JPEG compression for saving
- the disk space.
-
- 7.5 Other Formats
-
- Support for other formats is under consideration for the
- future versions of ImgFun. Please inform the author for
- supporting formats desired. Since this is a user-supported
- program, features desired from the feed back of users will
- be added, too. Also a lossless compression scheme for
- 256 color mapped images is under development. The goal is
- to compress GIF images to 60% of the original size losslessly.
-
-
-
-
-
- ImgFun.txt Speedy Software page 17
-
-
-
-
- 8. Function Usage:
-
- 8.1 File:
-
- 8.1.1 Load: Load an image to work.
- 8.1.2 View: View an image file.
- 8.1.3 Save: Save the loaded image 1.
- 8.1.4 Quit: Quit ImgFun.
-
- 8.2 Adjust:
-
- 8.2.1 Brighten: Brighten the loaded image.
- 8.2.2 Darken : Darken the loaded image.
- 8.2.3 Contrast:
- Adjust contrast by gray level remapping of
- the palette of the loaded image 1.
-
- 8.2.4 cOlor :
- Adjust the colors in the palette of the palette
- of the loaded image 1.
- Two functions, RGB and PSEUDO are implemented.
- Please use the on-line help system to get more
- information.
-
-
- 8.3 Set:
-
- 8.3.1 Background: Choose a background color.
- 8.3.2 Cut area :
- Set a cut area of the loaded image 1.
- 8.3.3 Directions:
- Set horizontal and vertical directions
- of the loaded image 1.
- 8.3.4 Threshold : View a binary map
- from the loaded image 1 for a given threshold
- on the gray level.
-
- 8.4 Transform:
-
- 8.4.1 Rescale :
-
- Rescale loaded image 1 to a different width or
- height. The new height and new width should be 25% to 400%
- of the old values and not exceeding the system limit. For
- images with 16 colors or fewer, only zero order interpolation
- is used. For images with more colors and the new values of
- heights and widths are within 150% of the old
- values, zero-order interpolation is used. For others first
- order interpolation is used. The result is remapped into the
- palette.
-
-
-
- ImgFun.txt Speedy Software page 18
-
-
-
- 8.4.2 Smooth:
- Smooth the loaded image 1 in the luminance component.
-
- 8.4.3 shArpen:
- Sharpen the loaded image 1 in the luminance component.
-
-
- These three functions treat the loaded image 1 as a
- true color image. After processing the image, ImgFun remapps
- the internal true color into the original palette.
-
- 8.4.4 rOtate:
- Rotate the loaded image 1 by 90, 180, or 270 degrees.
-
-
- 8.5 Options:
-
- 8.5.1 Display :
- Set the display mode and the starting display
- point (xmin ,ymin) in the screen.
- 8.5.2 card :
- This function is a new add-on in ver. 1.0. It
- allows the user to manual select the SVGA driver.
-
- 8.5.3 direcTory:
- IMAGE: Specify where image files are located.
- HELP : Specify where ImgFun.hlp resides.
-
- 8.5.4 Dither :
- ON or OFF. Use dithering or not when remapping
- internal true color images into a palette.
-
- 8.6 Utility:
-
- 8.6.1 Compress : JPEG compression
-
- 8.6.2 cOnvert :
- Do conversion between different formats, also
- decompression of JPEG images
-
- 8.6.3 sLide show: a manual slide show
-
- 8.7 Undo and Update:
-
- Undo (F2): Remove all the changes made since last update.
-
- Update(F4): Accept the current image and makes changes since
- the last update permanent on the loaded image 1.
-
-
-
-
-
-
- ImgFun.txt Speedy Software page 19
-
-
- 8.8 Swap (F3) :
- Swap the loaded image 1 and the loaded image 2.
-
- 8.9 DOS (F6) :Shell out to DOS.
-
- 8.10 Gray (F7) :
- Turn the loaded image 1 into a gray level image.
-
- The on line help system has more details about these functions.
-
-
-
-
-
- ImgFun.txt Speedy Software page 20
-
-
-
- Author:
-
- Here I have to say some special thanks to some people.
-
- Dr. Lane and the JPEG independent group: Some of the work in the
- JPEG part is based on JPEG Independent Group's work. I do
- appreciate their efforts in promoting the standard JPEG format.
-
- Haruyasu Yoshizaka, the author of the LHA package, and Fabrice
- Bellard, the author of the LZEXE package : Their packages do
- provide a lot convenience for lossless data compression in the pc
- platform.
-
- Steve Estvanik, ASP Author Membership Coordinator: For his
- patience in the reviewing process and comments on the ImgFun
- package.
-
- <Ver. 0.99>
-
- The program is written carefully to be really lean
- and fast under DOS.
-
- Hope you will enjoy the result.
- Thanks! 9/15/92
- <Ver. 1.00>
- This version adds in a manual configure function for the
- SVGA display driver and a new function, PSEUDO in the Adjust
- Color selection. The true color compression is left in a major
- upgrade in 1993. But stand alone programs for compressing 24 bit
- BMP and PCX images might be available in early 1993 in the bonus
- package for registered users. Please register to support this
- program and let you have the rights to obtain the latest bonus
- utilities in the ImgFun package.
- Thanks! 12/4/92
-
- Chin-Chi ,Hsu at Speedy Software
-
- author member of Association of Shareware Professionals
-
- 173 Franklin Ave. San Gabriel, CA 91775
-
- CompuServe ID : 71551,3641 (best way to contact me)
-
- TEL: 818-282-8018
-
- PS. All trademarks mentioned belong to the proper owners.
-