+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>) {