#!/usr/bin/perl
use 5.014;
my ($file, $size) = @ARGV;

open my $pgm, '-|', convert => (
	-compress => 'none',
	'+distort' => SRT => '0,0 1,.56 0',
	-thumbnail => $size || '66x23',
	$file => 'pgm:-'
) or die $!;
<$pgm> eq "P2\n" or die "ascii pgm input required\n";
<$pgm>; <$pgm>;  # ignore depth, dimensions

my @ch = split //, " .:coO@";
while (<$pgm>) {
	print $ch[ $_ * @ch >> 8 ] for /\d+/g;
	print $/;
}