#!/bin/sh
convert -compress none -resize 66x23 - pgm:- |
perl -nE '
$_ eq "P2\n" or die "ascii pgm input required\n" if $. == 1;
next if $. <= 3;

state @ch = split //, " .oO@";
print $ch[ $_ / 256 * @ch ] for /\d+/g;
print $/;
'