getImageAlphaChannel()) {
    $im->setImageAlphaChannel(Imagick::ALPHACHANNEL_SET);
}

$refl = $im;

$gradient = new Imagick();

$gradient->newPseudoImage($refl->getImageWidth(), $refl->getImageHeight(), 'gradient:transparent-white');

$refl->compositeImage($gradient, imagick::COMPOSITE_DSTOUT, 0, 0);

$canvas = new Imagick();

$width = $im->getImageWidth();
$height = $im->getImageHeight();

$canvas->newImage($width, $height, 'none');
$canvas->setImageFormat('png');

$canvas->compositeImage($im, imagick::COMPOSITE_SRCOVER, 0, 0);
$canvas->compositeImage($refl, imagick::COMPOSITE_SRCOVER, 20, $im->getImageHeight());
$canvas->writeImages("new.png", true);