RLESETBG(1) 1 (December 20, 1986) 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...
Page 1 (printed 12/1/98)