基于CIF-to-QCIF变换的压缩域视频水印算法

A Compression Domain Video Watermarking Algorithm Based on CIF-to-QCIF Transformation

现有视频水印算法的设计目标主要是对有损压缩、重量化编码等处理具有鲁棒性,但很少考虑视频帧格式变换因素,使水印对这类处理不具有鲁棒性。论文结合视频帧格式由CIF到QCIF的变换设计了一个压缩域的视频盲水印算法,水印被嵌入到CIF格式的视频流中,既可以从CIF视频中提取也可以从QCIF视频中提取,实验结果表明提出的算法对MPEG重编码以及CIF到QCIF的视频格式变换具有鲁棒性,而且整个嵌入提取过程都基于DCT域,具有较低的计算复杂度。

The aim of current video watermarking algorithms is to be robust to loss compression,re-quantization transformation,etc,but these algorithms are not robust to transformation of video format which isn＇t contemplated when designing the watermarking algorithm.A compressed-domain watermarking scheme which aligns with video format downtranscoding from the Common Intermediate Format（CIF） to the Quarter Common Intermediate Format（QCIF） is proposed in this paper.The watermark is embedded in CIF video stream while the watermark could be extracted from either CIF or QCIF video stream.The simulation results demonstrate that the proposed scheme is robust not only to MPEG recoding but also to CIF-to-QCIF video transcoding,this algorithm also achieves the low computational complexity because the embedding and extraction procedure of watermarking are all based on DCT domain.