public static function ImageHue(&$image, $hue, $saturation)
{
$width = imagesx($image);
$height = imagesy($image);
for ($x = 0; $x < $width; $x++) {
for ($y = 0; $y < $height; $y++) {
$rgb = imagecolorat($image, $x, $y);
$r = $rgb >> 16 & 0xff;
$g = $rgb >> 8 & 0xff;
$b = $rgb & 0xff;
$alpha = ($rgb & 0x7f000000) >> 24;
$hsl = ColorUtils::rgb2hsl(array('r' => $r, 'g' => $g, 'b' => $b));
$h = $hsl['h'] / 360;
$s = $hsl['s'] / 100;
$h += $hue / 360;
$s += $saturation / 100;
if ($h > 1) {
$h--;
}
if ($s > 1) {
$s--;
}
$hsl['h'] = $h * 360;
$hsl['s'] = $s * 100;
$rgb = ColorUtils::hsl2rgb($hsl);
imagesetpixel($image, $x, $y, imagecolorallocatealpha($image, $rgb['r'], $rgb['g'], $rgb['b'], $alpha));
}
}
}
/**
* Converts a hsl color to it's hex equivalent
* @param array $hsl
* @return string The hex string
*/
public static function hsl2hex($hsl)
{
$rgb = ColorUtils::hsl2rgb($hsl);
return ColorUtils::rgb2hex($rgb);
}