public function convertToImagebySize($slideNumber, $imageFormat, $width, $height)
    {


        $strURI = Product::$baseProductUri . '/slides/' . $this->getFileName() . '/slides/' . $slideNumber . '?format=' . $imageFormat . '&width=' . $width . '&height=' . $height;

        $signedURI = Utils::sign($strURI);

        $responseStream = Utils::processCommand($signedURI, 'GET', '', '');
        $v_output = Utils::validateOutput($responseStream);
        if ($v_output == '') {
            $outputPath = AsposeApp::$outPutLocation . 'output.' . $imageFormat;
            Utils::saveFile($responseStream, $outputPath);
            return $outputPath;
        } else {
            return $v_output;
        }
    }