public function convertLocalFile($inputPath, $outputPath, $outputFormat)
    {
        $str_uri = Product::$baseProductUri . '/words/convert?format=' . $outputFormat;
        $signed_uri = Utils::sign($str_uri);
        $responseStream = Utils::uploadFileBinary($signed_uri, $inputPath, 'xml');

        $v_output = Utils::validateOutput($responseStream);

        if ($v_output === '') {
            if ($outputFormat == 'html') {
                $saveFormat = 'zip';
            } else {
                $saveFormat = $outputFormat;
            }

            if ($outputPath == '') {
                $outputPath = AsposeApp::$outPutLocation . Utils::getFileName($inputPath) . '.' . $saveFormat;
            }

            Utils::saveFile($responseStream, $outputPath);
            return $outputPath;
        }
        else
            return $v_output;
    }