argument(0)->between(0, 100)->required()->value(); // get size of image $size = $image->getSize(); // build temp alpha mask $mask_color = sprintf('rgba(0, 0, 0, %.1F)', $transparency / 100); $mask = $image->getDriver()->newImage($size->width, $size->height, $mask_color); // mask image $image->mask($mask->getCore(), true); return true; } }