public function show() {

        switch ( $this->extension ) {
            case 'jpg':
            case 'jpeg':
                header("Content-type: image/jpeg");
                imagejpeg($this->imgDst);
                break;

            case 'gif':
                header("Content-type: image/gif");
                imagegif($this->imgDst);
                break;

            case 'png':
                header("Content-type: image/png");
                imagepng($this->imgDst);
                break;

            default:
                die("No image support in this PHP server");

        }
        return $this;
    }