php 图片合成imagick合成求助

      
        $c = 'http://img.321.design/15848202009121449251473.jpg';
        #底图
        $b = 'https://nimg7.';

        $ci = new \Imagick($c);
        $bi = new \Imagick($b);
        $bi->compositeImage($ci, \Imagick::COMPOSITE_IN , 0, 0);
        $path = "/public/product/"  . "9999.png";
        $bi->writeImage(ROOT_PATH . $path);



        $d = $path;
        $a = 'https://nimg7.';
        $d = new \Imagick($d);
        $imagick = new \Imagick($a);
        $imagick->compositeImage($d, \Imagick::COMPOSITE_OVERLAY , 0, 0);
        $path = "/public/product/"  . "9999.png";
        $imagick->writeImage(ROOT_PATH . $path);
        echo  $path;exit;