#!/usr/bin/perl -w
# Resize and convert image to text.

use strict;

die "$0 <input> <width> <height>\n" unless $#ARGV == 2;
my ($input, $width, $height) = @ARGV;

# Convert to 2 color PGM.
my $cmd = "anytopnm $input | " .
          "pamdepth 255 | " .
          "pnmscale -xsize=$width -ysize=$height | " .
          "pnmquant 2 | " .
          "ppmtopgm";
open my $pipe, "$cmd|" or die $!;

# Convert PPM to text, assuming first pixel is black and everything
# else is white.
my ($header, $header0, $blackpixel);
$header0 = "P5\012$width $height\012255\012";
$blackpixel = undef;

sysread($pipe, $header, length($header0)) or die $!;
die "Bad header" if $header ne $header0;

for(my $y = 0; $y < $height; $y++)
{
   my $scanline;
   sysread($pipe, $scanline, $width) or die $!;
   defined($blackpixel) or $blackpixel = ord($scanline);
   print join '', map {($_ == $blackpixel) ? ' ' : 'X'} unpack 'C*', $scanline;
   print "\n";
}
close $pipe;

exit 0;