AVG4(1) 1 (Nov 12, 1986) AVG4(1)
NAME
avg4 - Downfilter an image by simple averaging.
SYNOPSIS
avg4 [ -o outfile ] [ infile ]
DESCRIPTION
Avg4 downfilters an RLE image into a resulting image of
1/4th the size, by simply averaging four pixel values in the
input image to produce a single pixel in the output. If the
original image does not contain an alpha channel, avg4
creates one by counting the number of non-zero pixels in
each group of four input pixels and using the count to
produce a coverage value. While the alpha channel produced
this way is crude (only four levels of coverage) it is
enough to make a noticeable improvement in the edges of
composited images.
OPTIONS
infile
The input will be read from this file, otherwise, input
will be taken from stdin.
-o outfile
If specified, output will be written to this file,
otherwise it will go to stdout.
SEE ALSO
fant(1), rlecomp(1), smush(1), urt(1), RLE(5).
AUTHOR
Rod Bogart, John W. Peterson
BUGS
Very simple minded - more elaborate filters could be
implemented.
Page 1 (printed 12/1/98)
