Example

function addNoiseImageWithAttenuate($noiseType, $attenuate, $image_path, $channel)
{
    $imagick = new \Imagick(realpath($image_path));
    $imagick->addNoiseImageWithAttenuate($noiseType, $attenuate, $channel);
    header("Content-Type: image/jpeg");
    echo $imagick->getImageBlob();
}