Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
"Richard G. French" wrote: > > After 5.4 came out, there were a lot of posts about the disappearance > of the GIF writer and reader routines. Can any of you experts tell me > about the legality of using shareware C code that reads and writes > GIF files, originally used as part of the XV program that displays > lots of image types on UNIX boxes? The idea would be to write > wrapper routines that could call WriteGIF and ReadGIF in the XV > code so that GIF writing and reading could be restored in IDL. > > These routines are in the pub/xv subdirectory of > ftp.cis.upenn.edu > > If this is not legal, does it mean that XV is not legal, > either, even if you pay the registration fee? > > Has anyone come up with a legal scheme under UNIX to > read and write GIF files? If you have to pay a license fee, does > anyone know what the fee would be for a single user? > Thanks for any hints on workarounds. > Dick French http://www.imagemagick.org/ Seems to be the way to go. Some enterprising tester of Ronn Kling's book could even create a DLM which links to the ImageMagick libraries and write GIF's directly. Given that PNG is a better format (http://www.libpng.org/pub/png/pngintro.html), especially for the web, maybe the interim convert-from-png route is preferrable. We don't want to make writing GIF's *too* easy. For those who don't know of the GIF (or rather LZW compression) issue: http://cloanto.com/users/mcb/19950127giflzw.html JD
JD Smith wrote: > > > http://www.imagemagick.org/ > > Seems to be the way to go. Some enterprising tester of Ronn Kling's > book could even create a DLM which links to the ImageMagick libraries > and write GIF's directly. Given that PNG is a better format > (http://www.libpng.org/pub/png/pngintro.html), especially for the web, > maybe the interim convert-from-png route is preferrable. We don't want > to make writing GIF's *too* easy. For those who don't know of the GIF > (or rather LZW compression) issue: > http://cloanto.com/users/mcb/19950127giflzw.html > > JD That imagemagick site looks terrific - thanks for the tip. I am happy to discontinue creating gifs, but I have about 1000 gifs I've made already that I would like to be able to read! I am sure this is a problem for others as well, and it really is crippling to many people. I know several people who are not upgrading to IDL5.4 for just this reason. Dick