public static function resize( $src, $w, $h = 0, $crop = 'default', $force = false ) {
		if ( !is_numeric($w) && is_string($w) ) {
			if ( $sizes = self::find_wp_dimensions($w) ) {
				$w = $sizes['w'];
				$h = $sizes['h'];
			} else {
				return $src;
			}
		}
		$op = new Image\Operation\Resize($w, $h, $crop);
		return self::_operate($src, $op, $force);
	}