AVG4(1)                                                 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 pix-
       els 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.




1                         Nov 12, 1986                  AVG4(1)
