Enhances the contrast of a color image by adjusting the pixels color to span the entire range of colors available.
Original on left side, normalised on right.

Original on left side, normalised on right.
function normalizeImage($image_path, $channel)
{
    $imagick = new \Imagick(realpath($image_path));
    $original = clone $imagick;
    $original->cropimage($original->getImageWidth() / 2, $original->getImageHeight(), 0, 0);
    $imagick->normalizeImage($channel);
    $imagick->compositeimage($original, \Imagick::COMPOSITE_ATOP, 0, 0);
    header("Content-Type: image/jpg");
    echo $imagick->getImageBlob();
}