GFX Sensations 1

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GIFPCX V3.6 GIF -to- ZSoft PCX Graphics File Translator Copyright 1988,1989 by William J. Hinkle CIS [71121,3211] 02 Dec 1989 GIF and 'Graphics Interchange Format' are trademarks of CompuServe, Incorporated. an H&R Block Company === User's Guide === The GIFPCX program was created to allow graphics files created as GIF (Graphics Interchange Format) files to be used in various word processors and desktop publishing systems that use the PCX image format. PCX images originated with the ZSoft Corporation's PC-Paintbrush program for the IBM-PC, but have become something of a de facto standard in the PC world. GIFPCX creates black-and-white PCX image from color or black-and-white GIFs. To do this, the program translates the GIF file into a PCX bit-mapped raster graphics file. In the process, GIFPCX converts the GIF image's colors into shades of gray, which it tries to reproduce in the black-and-white PCX image. NOTE: GIFPCX DOES NOT CREATE COLOR PCX FILES! There are zillions of GIF files available on CompuServe in the QPICS, GALLERY, COMART, and CORNER forums, as well in other forums, and from other sources. Generally they are in color, which GIFPCX changes into grayscale and then dithers (default) or halftones. The translator is a single file: GIFPCX.EXE. A quick and dirty example: GIFPCX yergif will convert YERGIF.GIF to YERGIF.PCX in black and white. ========= THE CATCH ========= Note that this program is being released by the author, and is NOT supported by CompuServe Inc., or ZSoft Corporation, either. It is NOT public domain! This utility program GIFPCX.EXE was written by William J. Hinkle who retains the copyright. Copy and use the program freely. Distribute it to whomever you want. But: === Do NOT distribute modified versions. === Do NOT remove the copyright notice. === ALWAYS distribute with the documentation. If you feel that this program has been of some utility, please register by sending $10.00 to: William J. Hinkle 420 E.Boston Mills Rd. Hudson, OH 44236-1111 ========= OPERATION ========= First get a GIF image you want to integrate into your document. These are usually "paint" or "screen capture" images. GO PICS on CompuServe will lead you to a forum with all sorts of information on GIF images; GO QPICS, GO COMART, GO CORNER and GO GALLERY on CompuServe will lead you to collections of GIF images that you can download. Many on-line BBS's have GIF images available. You must have the GIF image in a file on disk; the file should have the standard .GIF file extension (i.e., fname.GIF). To create a .PCX file, type in: GIFPCX fname or GIFPCX fname.GIF or GIFPCX fname.GIF fname.PCX from the DOS command prompt. The .GIF extension is assumed if you do not specify one. The .PCX extension is assumed whether you specify one or not. The .PCX file name is made the same as the .GIF if not otherwise specified. Full DOS pathnames can be specified. You can specify just a directory (ending in \) or a drive (ending in :) instead of the second filename; the PCX file will use the name of the GIF file, with a PCX extension, and be placed on that path. The .GIF file will be translated to a black-and-white .PCX file. The .GIF file will not be erased. You can also specify scaling factors, but the defaults often work the best (see below). ================== WILDCARD FILENAMES ================== GIFPCX doesn't handle wildcard filenames, like *.GIF. But you can accomplish the same thing by using the DOS "FOR" command. See your DOS manual's section on Batch Commands for further info. To convert all of the GIFs in the current directory to PCX: FOR %f in (*.GIF) do GIFPCX %f =============== INTERLACED GIFS =============== Some GIF files are "interlaced" -- they are specially constructed for on-line viewing. GIFPCX will process this type of GIF file without complaint, but it has to temporarily create a special file while doing so. If you receive error messages about interlace processing, check that you have plenty of free space on your default disk. ============== COMPLEAT USAGE ============== If you invoke GIFPCX from DOS without any other parameters, it will display the following help message. This illustrates some of the other options: ----- GIF-to-PCX Translator: V3.6 ... Copyright 1988,1989 by W.J.Hinkle Usage: GIFPCX fname1 [fname2] [option] [option] ... where: fname1.GIF ... GIF format input file fname2.PCX ... ZSoft PCX file (B&W) (default is fname1.PCX) Command Line Options: /v ... reverse video /iN ... select sub-image N (default is 1) /cN ... change contrast by N% /bN ... change brightness by +/-N% (BEFORE contrast %) /wN ... index of color to change into "white" /p ... print pixel histogram data (colors used) /g ... equal color weighting for grayscale GIF /l ... linearize colors (ignore color maps) /eN ... error diffused dither, expanding xN (default is 1) /dN ... make dither pattern block NxN /hN ... make halftone pattern block NxN GIFPCX is a translator from CompuServe GIF files to ZSoft PCX graphics files - Black and White only! - for use in printed documents. The GIF colors are converted to grayscale intensity using the weighting: Red 30%, Green 59%, Blue 11%. You can specify that the GIF uses only gray tones with the /g flag; equal color weighting will then be used. The grayscale is dithered error diffused, by default. A pattern block size can be used instead: select with /dN, N=1,2,4 or 8 for pattern dither or with /hN, N=1,2,3 or 4 for pattern halftone. The /p option will print on-screen a histogram of the colors used in the GIF, their RGB color components, and their brightness. You can adjust the overall brightness with the /bN option (-100 <= N <= +100, in percentage brightness) and the contrast with the /cN option (N is a percentage multiplier). Eliminate a pesky background color by specifying /wN, where N is the index number of that color. All the pixels in that color are turned pure white. (followed by copyright and shareware info) ========== SUB-IMAGES ========== If your GIF file contains multiple sub-images, you can specify which one to extract and translate by specifying the /iN option, where N is the sub- image number 1,2,3... etc. Normally, you can ignore this option; the 1st (or only!) image will be translated. If there are additional sub-images beyond the one selected, a warning is issued and they are ignored. ==================== COLORS AND GRAYSCALE ==================== Most GIF files are in color. GIFPCX transforms the color mapping into intensity of grayscale using the above mentioned weights. If you know for a fact that the GIF uses gray tones only, you can specify the /g option to use equal color weights. Once in grayscale, the image can be either dithered (the default) or halftoned. Normally, you don't have to even think about this, but if you want to tweak things, and possibly improve your results, read on... Dithering tries to average the image brightness over a small area of the image. The default is to use retain the size of the image in both axes, and use error-diffused dithering. You can vary the multiplication factor by specifying the /eN option with N larger than 1, where N is the size multiplier. In other words, the default dithering is equivalent to /e1. This type of dithering tends to ease problems image artifacts (those weird "plaid" patterns) if you later have to scale the image. You can often improve your results, at the cost of larger file sizes and slower processing, by specifying /e2, /e3, /e4, etc. The larger the number after /e, the larger the PCX file and slower the processing -- but the better the resolution! If you specify the /dN option (/d1, /d2, /d4, or /d8), the image size is not multiplied and a patterned dither is used with an NxN dither block. This can give smaller PCX files, but not very good visual results. Better than pattern dither is (simulated) halftoning, which replaces each GIF pixel with a block of on/off pixels that have a corresponding optical density. Halftoning will be done instead of dithering if you specify the /hN option (which will halftone with an NxN block). For example: /h1, /h2, /h3, or /h4. ============= REVERSE VIDEO ============= Normally GIFPCX flips the photometric interpretation of the GIF file colors: the brightest colors have the fewest pixels in the PCX file. This is because GIF files are generally optimized for screen viewing, but word processors will (eventually) put the image on paper. However, if you WANT a reverse video effect, use the /v option switch. ========================== KILLING THE COLOR MAPPING ========================== You can override the GIF file's color map by specifying the /l option (that's an "el", not a "one"). This "linearizes" the color mapping: color indices will be transformed directly into grayscale without worrying about how bright the colors really ought to be. This sometimes gives a more detailed, though probably less accurate, image. It may be most useful for charts and such. ======================= BRIGHTNESS AND CONTRAST ======================= The /bN option can be specified to adjust the brightness the image. The effect is to add N percent of maximum brightness to the image. The factor N can range from -100 to +100 percent. If not specified, no change in the brightness is made. For example: /b-25 lowers the brightness by 25%. The /cN option can be specified to adjust the contrast of the image. The effect is to multiply each grayscale intensity value by N%. The factor N can be greater or less than 100. If not specified, the contrast is left at 100%. For example: /c85 give 85% contrast. The contrast adjustment is applied AFTER the brightness adjustment. The histogram option can give you an idea of what kind of adjustments to make to the brightness and contrast; see below. NOTE: For many high-color images to print satisfactorily, a rule of thumb is to add 20 or 30 percent brightness: /b20 to /b30. Otherwise overlapping printer dots cause images to appear very dark -- but this varies radically with the word processor and printer, and even with the state of the printer ribbon! =================== WHITEOUT BACKGROUND =================== Simple GIFs (as found in QPICS, for example) often have a solid color background that will just clutter things up when printed in black-and-white. You can eliminate that color by specifying its color index as N in the /wN option. This will yield a nice clear background in the PCX image. But, how to find out the background color? Print out the histogram (see below) and look for a color that is used FAR more often than the rest. That is probably the background color. Or simply experiment. =============== PRINT HISTOGRAM =============== The /p option causes a histogram to be kept on the distribution of color indices in the GIF image. The RGB levels and relative brightness of each color, as well as the number of occurences of each value, are printed on the screen when the translation is complete. Here's a technique that is often helpful in improving the resulting PCX image: Translate your GIF file, using the /p option to get a histogram. You can re-direct the histogram printout to a file or the printer with DOS file redirection, e.g.: GIFPCX YERGIF /p >lpt1 If you like the resulting PCX file, you're done! But if not, take a look at the histogram. See if the lowest brightness actually used in the picture is well above 0%. If so, you might want to adjust the brightness downward. See also if the total range of brightness is well under 100%. If so, you might want to adjust the contrast upward to avoid a washed-out look (especially if you adjust the brightness downward). ======== EXAMPLES ======== 1) Suppose you have a GIF file called "earthm.gif". You want to create a PCX file version of this image without worrying about the details. You can translate this to a PCX file by typing (at the DOS prompt): GIFPCX earthm and you will see something like: ----- GIF-to-PCX Translator: V3.6 ... Copyright 1988, 1989 by W.J.Hinkle From GIF 640x350x16 file: earthm.gif to PCX 640x350 file: earthm.pcx dithered error diffused with +0% brightness, 100% contrast. ----- Note that both the GIF image resolution and color range are shown: GIF Width x Height x # of Colors Also shown is the final PCX image resolution: PCX Width x Height 2) Suppose you have a GIF file called "yikes.gif". You can translate this to a PCX file by typing (at the DOS prompt): GIFPCX yikes /h4 and you will see something like: ----- GIF-to-PCX Translator: V3.6 ... Copyright 1988, 1989 by W.J.Hinkle From GIF 156x131x16 file: yikes.gif to PCX 624x524 file: yikes.pcx halftoned into a 4x4 pixel matrix with +0% brightness, 100% contrast. ----- 3) Suppose you have a black and white clipart GIF file called "barn.gif". You can translate this to a PCX file by typing (at the DOS prompt): GIFPCX barn and you will see something like: ----- GIF-to-PCX Translator: V3.6 ... Copyright 1988, 1989 by W.J.Hinkle From GIF 280x280x2 file: barn.gif to PCX 280x280 file: barn.pcx ----- Note that no dithering or halftoning information is shown for 2-color (aka monochrome) GIFs -- they are simply changed into black and white PCX files without further processing. This is true for ANY 2-color GIF, even if it isn't black and white (say, blue and white). =========== ERROR CODES =========== If an error occurs within GIFPCX, it will print an error message and terminate the program. You may be left with a partial PCX file on-disk, so just delete that (or it will be overwritten if you try again). The errors messages are in the form: Error #NNNN: Message where the message is pretty generic, and indicates the name of the offending file, if any. The error numbers are mostly "standard" DOS errors, and a few are peculiar to GIFPCX. DOS Error Meaning ----- ------- 0 Cause of error unknown 1 Invalid DOS function 2 File not found 3 Path not found 4 Too many files opened 5 Access denied 6 Invalid handle 7 Memory control blocks destroyed 8 Insufficient memory 9 Invalid memory block address 10 Invalid environment 11 Invalid format 12 Invalid access code 13 Invalid data 15 Invalid drive code 16 Can't remove current directory 17 Not same device 18 No more files 19 Can't write on protected device 20 Unknown unit 21 Drive not ready 22 Unknown command 23 Data error 24 Bad request structure length 25 Seek error 26 Unknown media type 27 Sector not found 28 Printer paper alarm 29 Write fault 30 Read fault 31 General failure 32 Sharing violation 33 Lock violation 34 Invalid disk change, 35 FCB unavailable 36 Sharing buffer overflow DOS Error Meaning ----- ------- 50 Network request not supported 51 Remote computer not listening 52 Duplicate name on network 53 Network name not found 54 Network busy 55 Network device no longer exists 56 Net BIOS command limit exceeded 57 Network adaptor hardware error 58 Incorrect response from network 59 Unexpected network error 60 Incompatible remote adaptor 61 Print queue full 62 Not enough space for print file 63 Print file was deleted 64 Network name was deleted 65 Access denied 66 Incorrect network device type 67 Network name not found 68 Network name limit exceeded 69 Net BIOS session limit exceeded 70 Temporarily paused 71 Network request not accepted 72 Print or disk redirection is paused 80 File exists 82 Cannot make directory entry 83 Fail on INT 24 84 Too many redirections 85 Duplicate redirection 86 Invalid password 87 Invalid parameter 88 Network device fault GIFPCX Error Meaning ------ ------- 8100 Unknown command line switch 8101 Can't use enough memory for operation (image too large?) 8102 Disk is full 8103 Input file shorter than expected 8104 Sub-image does not exist 8105 Ctrl-Break (Ctrl-C) pressed 8200 GIF input file header not as expected 8201 GIF input file format not as expected 8202 Unknown GIF format ID 8203 Error decoding GIF image ====== HELP!? ====== Should you have any difficulties using this program, you can contact me (Bill Hinkle) through CompuServe EMAIL to [71121,3211], in the PICS forum, or at the address on the first page of this document. General feedback is welcome, especially on better methods of color reduction, grayscale halftoning and dithering, and problem GIF files. Thanks to Bob Cancilla [76077,354] for his prototype testing & help on the original GIF2BIT for Lotus Manuscript. Thanks to Jeff Lewis [72717,1033] for ideas on halftoning and dithering. Thanks to Kyle Powell [76044,2215] for his public domain LZW decoder 85GIF. Thanks to Tom Pfau for his public domain LZW decoder. Thanks to Floyd & Steinberg for the error diffused dither algorithm. Thanks to Larry Brennan and Millard Brown for their comments and suggestions. Thanks to the many CIS beta testers and folks who reported problems. ============= REVISION INFO ============= * Version number Date Explanation * * -------------- ------ -------------------------- * * 3.4 07 Nov 89 derived from GIF2BIT and GIF2WPG * * 3.5 02 Dec 89 improved due to some good advice * * 3.6 17 Dec 89 tweaked for B&W GIF Clipart * ----------------end-of-author's-documentation--------------- Software Library Information: This disk copy provided as a service of The Public (Software) Library We are not the authors of this program, nor are we associated with the author in any way other than as a distributor of the program in accordance with the author's terms of distribution. Please direct shareware payments and specific questions about this program to the author of the program, whose name appears elsewhere in this documentation. If you have trouble getting in touch with the author, we will do whatever we can to help you with your questions. All programs have been tested and do run. To report problems, please use the form that is in the file PROBLEM.DOC on many of our disks or in other written for- mat with screen printouts, if possible. The P(s)L cannot de- bug programs over the telephone. Disks in the P(s)L are updated monthly, so if you did not get this disk directly from the P(s)L, you should be aware that the files in this set may no longer be the current versions. For a copy of the latest monthly software library newsletter and a list of the 2,000+ disks in the library, call or write The Public (Software) Library P.O.Box 35705 Houston, TX 77235-5705 (713) 524-6394