Free the image clearing resources associated with it.
|
public free ( |
||
| $image | ||
| return | ||
/**
* Generate and get the difference hash of image.
*
* @param Image $image
*
* @param Editor $editor
*
* @return string
*/
public function hash($image, $editor)
{
$width = 9;
$height = 8;
$image = clone $image;
// Make sure we are working on the clone if Image is passed
$editor->resizeExact($image, $width, $height);
// Resize to exactly 9x8
$gd = $image->getCore();
// Build hash
$hash = '';
for ($y = 0; $y < $height; $y++) {
// Get the pixel value for the leftmost pixel.
$rgba = imagecolorat($gd, 0, $y);
$r = $rgba >> 16 & 0xff;
$g = $rgba >> 8 & 0xff;
$b = $rgba & 0xff;
$left = floor(($r + $g + $b) / 3);
for ($x = 1; $x < $width; $x++) {
// Get the pixel value for each pixel starting from position 1.
$rgba = imagecolorat($gd, $x, $y);
$r = $rgba >> 16 & 0xff;
$g = $rgba >> 8 & 0xff;
$b = $rgba & 0xff;
$right = floor(($r + $g + $b) / 3);
// Each hash bit is set based on whether the left pixel is brighter than the right pixel.
if ($left > $right) {
$hash .= '1';
} else {
$hash .= '0';
}
// Prepare the next loop.
$left = $right;
}
}
$editor->free($image);
return $hash;
}
