private function _output_file($file_data)
    {
        // Create the headers
        $this->_create_headers($file_data);
        
        // Get the file data
        $data = file_get_contents($file_data);
        
        // Send the image to the browser in bite-sized chunks
        $chunk_size = 1024 * 8;
        $fp = fopen('php://memory', 'r+b');
        
        // Process file data
        fwrite($fp, $data);
        rewind($fp);
        while (! feof($fp)) {
            echo fread($fp, $chunk_size);
            flush();
        }
        fclose($fp);
        
        exit();
    }