The new detector can improve the performance of the watermark detector by the pre - processing to the attacked watermarked image before watermarking detecting . 2 . a new robust watermarking algorithm based on pixels permutation is proposed in this paper 在水印信息检测之前首先对待测图像进行与其所受处理具有互补性的预处理,在相同的水印容量下可以有效的提高水印信息的鲁棒性。