#!/bin/sh
f=$1
case "$1" in
*.[Ii][Ff][Ff])
    f="${1%.[Ii][Ff][Ff]}";;
*.[Ll][Bb][Mm])
    f="${1%.[Ll][Bb][Mm]}";;
*.[Ii][Ll][Bb][Mm])
    f="${1%.[Ii][Ll][Bb][Mm]}";;
*.[Hh][Aa][Mm])
    f="${1%.[Hh][Aa][Mm]}";;
esac
ilbmtoppm "$1" 2>/dev/null | pnminvert | ppmquant -map ~/bwmap | \
	ppmtopgm | pgmtopbm | pnmtopng -force >"$f.png"
.