www.pudn.com > giflib12.zip > README.1ST

	The Graphics Interchange Format(c) is the Copyright property of 
CompuServe Incorporated. GIF(sm) is a Service Mark property of CompuServe 
Incorporated. 
 
	This is a package I wrote so that images can be generated as easy as 
possible using GIF format. I needed such routines, and since I did not find 
anything like this (at list not free) I decided to write one... 
	This package is FREE for non commercial usage. You can do whatever 
you like with it provided you do not charge anything for it or for a program 
that uses it. More then that, if you release the source for your program, the 
source of this package you used should also be included (with my name on 
it...). You may NOT charge money for the sources as well, in that case. 
	I am releasing the sources since lots of peoples expressed interest 
in such a beast, on usenet, in the last few month. 
	I will NOT be hold responsible for any damage of any kind it may 
cause you. Use it at your own risk. 
	In order to compile it, please read the file COMPILE.ME. I uses TC++ 
2.0 so other compiler owners are on their own. The package has been ported to 
unix machine on various platforms (see compile.me). 
	You will find .\doc with documents on all the utilities and the library 
itself. 
	Only one of the images on .\pic was actually generated by me - 
solid2.gif, which is binary image rendered using a solid modeller I have 
developed named IRIT. The other two were released to usenet few month ago. 
I do not think so, but let me know if I violate anything here. 
	Few final remarks. While 'playing' with the GIF format, I found few 
holes in it, or in some of its implementations: 
1. There is no explicit way one can specify comments in images, which can be 
   extremely useful. I used one of the extensions block to implements that. 
   The problem is that some of the gif viewer I tested (no names) died on 
   extension block (!?), so I decided not to use them in any of the utilities 
   although the library do support it, and if you are going to use only it 
   you can safely use the comments calls. Any better solution? 
2. Some viewer even ignore the fact that one GIF file can hold few images. 
   I consider this property extremely useful (some of the utilities actually 
   manipulate exactly that - gifasm for example), and fully support it. I 
   think that a failure of a view program (or any GIF manipulator) here, 
   should be considered a bug. 
3. One problem in the GIF format, I dont have simple solution to: it is the 
   limit of only 8bits per color. The importance of bigger width, is not only 
   for higher image quality. One can save other pixel properties in addition, 
   such as coverage (alpha channel as it is called in the rle utah raster 
   toolkit). The only solution I can thing of, is to generate few GIF files 
   in parallel - one for the pixel color, and the other for coverage. The 
   coverage property is extremely useful for utilities such as gifbg - back 
   ground color generator, and which can be composed with the image using 
   gifcomb. 
 
have fun 
 
Gershon 
gershon@cs.utah.edu