Man Linux: Main Page and Category List


       giftrans  -  transform  gif  from  gif87  to  gif89,  making  one color


       giftrans [options] [-o filename] filename


       giftrans converts any GIF file into a GIF89a.  Allows for  setting  the
       transparent  or  background  color, changing colors, adding or removing
       comments. Also code to analyze GIF contents.


       -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. Of course, beware that shells will often consider the # character
       to start a comment and so you may have to escape it!


       To convert the white background of a gif file to transparent, use

            giftrans -t #ffffff file.gif > transparentfile.gif


       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 specified, 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 original data,  use
              with caution, best only with then -L option.


       Copyright (c) 24.2.94 by Andreas Ley <>

       Permission  to  use, copy, modify, and distribute this software 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 1.11 - 21.7.94
              Moved Plain Text Extension to the Extensions  section  where  it
              Accept Unknown Extension Labels
              Incorporated MS-DOS port by (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 transparent 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
              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 (


       Thanx for bug reports, ideas and fixes to

     (Patrick Atoon)

     (Wes Barris)

     (Patrick M. Fitzgerald)

     (frans van hoesel)

     (Dan Boardman)

     (Ken Weiss)

     (Chuck Musciano)

     (Torsten Heycke)

     (Colin Law)

     (Joseph C. Walker)

     (Bjorn Borud)

     (CJS Vance)

     (Peder Langlo)

     (Ian Rutson)

     (Nicolas Pioch)

              john@charles.CS.UNLV.EDU (John Kilburg)

     (Enzo Michelangeli)


       xv(1), giftoppm(1), ppmtogif(1)