摘要： 在视频水印的评价标准中,鲁棒性和透明性是一对非常重要的性能指标,同时也是一对相互制约的指标。 已有的视频水印算法对上述2 个指标都采用折衷的方法,为保证透明性通常不能兼顾水印的鲁棒性。为解决上述 问题,提出一种可移除数字视频水印算法。在嵌入水印时,不限制水印嵌入的强度,以保证水印信息的鲁棒性,而 嵌入后的视频在播放时,需要经过一个水印移除的过程,移除水印后的视频在视觉效果上与原视频接近或完全一 致,以满足水印的透明性。同时,用户需提供合法的密钥,以保证水印移除的正确性,并提高水印算法的安全性。 测试结果表明,该算法对分辨率放缩、视频重编码及码率压缩的操作具有较强的鲁棒性。

关键词: 可逆水印, 可移除水印, 视频水印, 码分多址, 离散余弦变换

Abstract: To evaluate the performance of watermark algorithm,robustness and transparency is a couple of very important standards. As in many proposed algorithms, the insurance of transparency is based on the reduction of robustness. This paper describes a removable video watermark algorithm. This algorithm can solve the problem mentioned before. To improve the robustness, the proposed algorithm does not limit the strength of watermark embedding. Before the video playing,the watermark in the media is removed according to the user’ s secret key, unauthorized key will lead to an additional distortion on video,which improves the security of the watermark algorithm.Experimental results imply the proposed algorithm has strong robustness against to the process of resolution change, recoding and bit-rate decreasing.

Key words: revisable watermark, removable watermark, video watermark, Code Division Multiple Access(CDMA), Discrete Cosine Transform(DCT)

中图分类号: 

• TP37