Создаем белый прямоугольник внизу изображения. [Create a white rectangle at the bottom of the image.]
$image = "http://localhost/files/upload/399000/399357/cmsimage8KEGF3.jpg";
list($width, $height) = getimagesize($image);
$gmagicDraw = new GmagickDraw();
$gmagicDraw->setfillcolor("#fff");
$gmagicDraw->rectangle(0, $height - $height * 0.02, $width, $height);
$gImage = new Gmagick();
$gImage->readImage($image);
$gImage->drawimage($gmagicDraw);
$gImage->writeimage(DOCROOT . "files/temp/img". $someId);