DragonFly On-Line Manual Pages

RLESETBG(1)            DragonFly General Commands Manual           RLESETBG(1)

NAME
       rlesetbg - Set the background value in the RLE header.

SYNOPSIS
       rlesetbg [ -{DO} ] [ -c bgcolor ...  ] [ -o outfile ] [ infile ]

DESCRIPTION
       rlesetbg sets the background color field in the image header of an
       RLE(5) image (none of the actual pixels are changed).  If infile isn't
       specified, the image is read from stdin.

       The background color in the header is used to save space in the run-
       length encoded file.  Runs of background-colored pixels longer than 2
       pixels are simply not saved.  (Doing this for runs of 1 or 2 background
       pixels can make the saved image larger than if no encoding were done.)
       Therefore, changing the background color with rlesetbg may still leave
       some pixels saved in the original background color.  The -D option will
       delete the background color altogether from the header; this can be
       useful in certain circumstances, but can also lead to very strange
       results.

OPTIONS
       -D     Delete any background specification that might be present.

       -O     Specifies that the image has no background, it overlays existing
              images.

       -c bgcolor ...
              Specifies the color values to set the background to.  There
              should be at least as many values as there are color channels in
              the image.  Use -- or another option to separate the list of
              colors from infile.

       -o outfile
              If specified, the output will be written to this file.  If
              outfile is "-", or if it is not specified, the output will be
              written to the standard output stream.

AUTHORS
       John W. Peterson and Rod Bogart

SEE ALSO
       repos(1), urt(1), RLE(5).

BUGS
       This should really be part of a single program that does all header
       munging...

4th Berkeley Distribution      December 20, 1986                   RLESETBG(1)