#the pixel grid
my @pixel_id; # this array stores all of the unique ids for each pixel
$pixel_counter = 0;
for(my $j = $init_y; $j < $canv_height; $j = $j + $pixel_height)
{
    <for(my $i = $init_x; $i < $canv_width;$i = $i + $pixel_width)
    {
        
      $pixel_id[$pixel_counter] = $canvas -> createRectangle($init_x,$init_y,$next_x,$next_y,-fill => "white",-outline => "gray");
        $init_x = $next_x;              
        $next_x = $next_x + $pixel_width;
        $pixel_counter++;
    }
    $init_x = 0;
    $next_x = $pixel_width;
    $init_y = $next_y;                   
    $next_y = $next_y + $pixel_height;   
}