Here is some PHP that will find map hack of the screenshots. Like you said Mistral it might give false positive if ss is not from start of game. But even for small maps I think it's very rare that you scout every black pixel on map...
$image_name = '041658_L45.png';
$image_src = '/ss/May14/12349_chopppppppppp/'.$image_name;
$image = imagecreatefrompng($image_src);
$totalBlack = 0;
$area = array(
array(26, 27),
array(153, 27),
array(26, 154),
array(153, 154)
);
// 26 and 153 is one pixel in to avoid first black pixel in row.
// x and y + 2 to count every second pixel, to avoid counting fog of war.
for ($y = $area[0][1]; $y < $area[2][1]; $y = $y + 2 ) {
for($x = $area[0][0]; $x < $area[3][0]; $x = $x + 2 ) {
$value = imagecolorat($image, $x, $y);
if($value == 0){
$totalBlack++;
}
}
}
// Found map hack
if($totalBlack != 0){
copy($image_src, '/ss/suspected/'.$image_name);
}