public static final function thumb($mode, $source, $target, $width, $height = null, $color = null)
{
if ($height === null) {
$height = $width;
}
if ($mode === "square") {
Magic::square($source, $target, $width);
} elseif ($mode === "rational") {
Magic::rational($source, $target, $width, $height);
}
}