for my $index (0..5) {
    my $thisrow = $nextrow - $index;
    print "processing row/column/bit $thisrow/$col/$subcol: " . substr($binimage[$thisrow], $col, 1) . "\n";
    printf ("Incoming byte is %d/%x/%8b/%s.  Test bitmask is %d/%x/%8b/%s.\n", 
	substr($binimage[$thisrow], $col, 1),substr($binimage[$thisrow], $col, 1),substr($binimage[$thisrow], $col, 1),
            unpack('B8',substr($binimage[$thisrow], $col, 1)), 
	2**(7-$subcol), 2**(7-$subcol), 2**(7-$subcol), unpack('B8', 
            2**(7-$subcol)));
    substr ($char, $index + 2, 1) = ((substr($binimage[$thisrow], $col, 1)) & 2**(7-$subcol))? "1" : "0";  # Update tracker where a "1" is found!
}