Original on left side, normalised on right.
Touch/mouse over to see original View modified in new window.
Image
Channel
function normalizeImage($imagePath, $channel)
{
    $imagick = new \Imagick(realpath($imagePath));
    $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();
}