GIFTRANS(l)
NAME
giftrans - transform gif from gif87 to gif89, making one
color transparent
SYNOPSIS
giftrans [options] [-o filename] filename
DESCRIPTION
giftrans converts any GIF file into a GIF89a. Allows for
setting the transparent or background color, changing col-
ors, adding or removing comments. Also code to analyze GIF
contents.
OPTIONS
-h Print short help on stdout.
-t Specify the transparent color
-T Index of the transparent color is the background
color index
-B Specify the transparent color's new value
-b Specify the background color
-g Change a color in the global color table
-c Add a comment
-C Remove old comment
-l Only list the color table
-L Verbose output of GIFs contents
-V Verbose output while converting
-o Redirect stdout to a file
-e Redirect stderr to a file
Colors may be specified as index, as rgb.txt entry or in
the #rrggbb form.
EXAMPLE
To convert the white background of a gif file to transpar-
ent, use
giftrans -t #ffffff file.gif > transparentfile.gif
BUGS
This program has been tested on a HP9000/720 with HP-UX
A.08.07 In this environment, neither lint -u nor gcc -Wall
produce any messages. If you encounter any errors or need
to make any changes to port it to another platform, please
contact me.
Known bugs:
-B flag won't work if there's an Extension between
the Global Color Table and the Image Descriptor (or
Graphic Control Extension). If -V has been speci-
fied, a Warning Message will be displayed. Will be
fixed in 2.0
Always outputs GIF89a. Shouldn't do this if version
is newer.
-D option may output changed data instead of origi-
nal data, use with caution, best only with then -L
option.
COPYRIGHT
Copyright (c) 24.2.94 by Andreas Ley <ley@rz.uni-karl-
sruhe.de>
Permission to use, copy, modify, and distribute this soft-
ware for any purpose and without fee is hereby granted,
provided that the above copyright notice appears in all
copies. This software is provided "as is" and without any
express or implied warranties.
VERSION HISTORY
Version 1.11 - 21.7.94
Moved Plain Text Extension to the Extensions sec-
tion where it belongs
Accept Unknown Extension Labels
Incorporated MS-DOS port by enzo@hk.net (Enzo
Michelangeli)
Added -o and -e options to redirect stdout and
stderr
Added -D debug flag
Version 1.10.2 - 22.6.94
Support for -DRGBTXT flag
Version 1.10.1 - 21.6.94
Different rgb.txt file FreeBSD/386BSD
Version 1.10 - 19.6.94
Added option to change a color in the global color
table
Added option to change the color for the transpar-
ent color index
Version 1.9.1 - 7.6.94
Different rgb.txt files for X11 and Open Windows
Version 1.9 - 1.6.94
Fixed a bug which caused color names to be
rejected.
Version 1.8 - 30.5.94
Accept #rrggbb style arguments.
Do nothing if rgb-color not found in GIF.
Version 1.7 - 16.5.94
Added -l option to only list the color table.
Added -L option for verbose output without creating
a gif. Added -b option to change the background
color index.
Display all matching color names for color table
entries.
Fixed a bug which caused bad color names if rgb.txt
starts with whitespace.
Doesn't use strdup anymore.
Fixed =& bug on dec machines.
Version 1.6 - 5.4.94
Added color names recognition.
Version 1.5 - 15.3.94
Added basic verbose output to analyze GIFs.
Version 1.4 - 8.3.94
Fixed off-by-one bug in Local Color table code.
Added option to add or remove a comment.
Transparency is no longer the default.
This man file made 9.8 from documentation in the program
source code by Kai Nordlund knordlun@fltxa.helsinki.fi.
THANKS
Thanx for bug reports, ideas and fixes to
patricka@cs.kun.nl (Patrick Atoon)
wes@msc.edu (Wes Barris)
pmfitzge@ingr.com (Patrick M. Fitzgerald)
hoesel@chem.rug.nl (frans van hoesel)
boardman@jerry.sal.wisc.edu (Dan Boardman)
krweiss@chip.ucdavis.edu (Ken Weiss)
chuck@trantor.harris-atd.com (Chuck Musciano)
heycke@camis.stanford.edu (Torsten Heycke)
claw@spacsun.rice.edu (Colin Law)
jwalker@eos.ncsu.edu (Joseph C. Walker)
Bjorn.Borud@alkymi.unit.no (Bjorn Borud)
Christopher.Vance@adfa.oz.au (CJS Vance)
pederl@norway.hp.com (Peder Langlo)
I.Rutson@bradford.ac.uk (Ian Rutson)
Nicolas.Pioch@enst.fr (Nicolas Pioch)
john@charles.CS.UNLV.EDU (John Kilburg)
enzo@hk.net (Enzo Michelangeli)
DISTRIBUTION
Original distribution site is
ftp://ftp.rz.uni-karl-
sruhe.de/pub/net/www/tools/giftrans/giftrans.c
To compile for MS-DOS, you need getopt:
ftp://ftp.rz.uni-karl-
sruhe.de/pub/net/www/tools/giftrans/getopt.c
MS-DOS executable can be found at
ftp://ftp.rz.uni-karl-
sruhe.de/pub/net/www/tools/giftrans/giftrans.exe
A template rgb.txt for use with the MS-DOS version can
be found at
ftp://ftp.rz.uni-karl-
sruhe.de/pub/net/www/tools/giftrans/rgb.txt
Additional info can be found on
http://melmac.corp.harris.com/transpar-
ent_images.html
SEE ALSO
xv(1) giftoppm(1) ppmtogif(1)