elFinder\elFinderVolumeDriver::gdImage PHP Method

    protected function gdImage($image, $filename, $destformat, $mime)
    {
        if ($destformat == 'jpg' || $destformat == null && $mime == 'image/jpeg') {
            return imagejpeg($image, $filename, 100);
        }
        if ($destformat == 'gif' || $destformat == null && $mime == 'image/gif') {
            return imagegif($image, $filename, 7);
        }
        return imagepng($image, $filename, 7);
    }