Assuming unifont or similar appearance.
-convert -compress none -resize 66x23 - pgm:- |
+convert -compress none +distort SRT '0,0 1,.56 0' -thumbnail ${1:-66x23} - pgm:- |
perl -e '
<> eq "P2\n" or die "ascii pgm input required\n";
<>; <>; # ignore depth, dimensions
perl -e '
<> eq "P2\n" or die "ascii pgm input required\n";
<>; <>; # ignore depth, dimensions
-my @ch = split //, " .oO@";
+my @ch = split //, " .:coO@";
while (<>) {
print $ch[ $_ * @ch >> 8 ] for /\d+/g;
print $/;
while (<>) {
print $ch[ $_ * @ch >> 8 ] for /\d+/g;
print $/;