public function apply($image)
{
// Localize vars
$width = $image->getWidth();
$height = $image->getHeight();
$old = $image->getCore();
$pixels = array();
$new = imagecreatetruecolor($width, $height);
for ($y = 0; $y < $height; $y++) {
for ($x = 0; $x < $width; $x++) {
// row 0
if ($x > 0 and $y > 0) {
$matrix[0][0] = $this->getColor($old, $pixels, $x - 1, $y - 1);
} else {
$matrix[0][0] = $this->getColor($old, $pixels, $x, $y);
}
if ($y > 0) {
$matrix[1][0] = $this->getColor($old, $pixels, $x, $y - 1);
} else {
$matrix[1][0] = $this->getColor($old, $pixels, $x, $y);
}
if ($x + 1 < $width and $y > 0) {
$matrix[2][0] = $this->getColor($old, $pixels, $x + 1, $y - 1);
} else {
$matrix[2][0] = $this->getColor($old, $pixels, $x, $y);
}
// row 1
if ($x > 0) {
$matrix[0][1] = $this->getColor($old, $pixels, $x - 1, $y);
} else {
$matrix[0][1] = $this->getColor($old, $pixels, $x, $y);
}
if ($x + 1 < $width) {
$matrix[2][1] = $this->getColor($old, $pixels, $x + 1, $y);
} else {
$matrix[2][1] = $this->getColor($old, $pixels, $x, $y);
}
// row 1
if ($x > 0 and $y + 1 < $height) {
$matrix[0][2] = $this->getColor($old, $pixels, $x - 1, $y + 1);
} else {
$matrix[0][2] = $this->getColor($old, $pixels, $x, $y);
}
if ($y + 1 < $height) {
$matrix[1][2] = $this->getColor($old, $pixels, $x, $y + 1);
} else {
$matrix[1][2] = $this->getColor($old, $pixels, $x, $y);
}
if ($x + 1 < $width and $y + 1 < $height) {
$matrix[2][2] = $this->getColor($old, $pixels, $x + 1, $y + 1);
} else {
$matrix[2][2] = $this->getColor($old, $pixels, $x, $y);
}
$edge = $this->convolve($matrix);
$edge = intval($edge / 2);
if ($edge > 255) {
$edge = 255;
}
$color = imagecolorallocate($new, $edge, $edge, $edge);
imagesetpixel($new, $x, $y, $color);
}
}
imagedestroy($old);
// Free resource
// Create and return new image with updated core
return new Image($new, $image->getImageFile(), $width, $height, $image->getType());
}
