#!/bin/sh
if ( [ -z "$1" ] || [ c"$1" = c"-h" ] ) ; then
cat << EOF >> /dev/stderr
USAGE:  overlay [emphasize] [opts] file1.pnm [file2.pnm | <file2.pnm] > out.pnm
DESCR:  overlays two images.  emphasize makes 1st less transparent than 2nd.
        this is an example script of one use of pnmcomp(1)
EOF
exit
fi
alpha="-alpha grey.pgm"
[ c"$1" = c"emphasize" ] && shift && alpha="-alpha grey80.pgm"
pnmcomp $alpha $*
