use GD::Simple;
my $png = GD::Image->newFromPng('test.png');  my @sw;
my ($width, $height) = $png->getBounds;
for my $x ( 0 .. $width-1 )      
  { for my $y ( 0 .. $height-1 ) 
    { $sw[$y].=getPixel($x,$y); 
    } 
  } 
 sub getPixel
 { my $p;
   my ($index) = $png->getPixel($_[0],$_[1]);
   my ($r,$g,$b) = $png->rgb($index);
   if ($b>128 || $r>128) {$p=0;} else {$p=1;}
   return $p;
 }