Analysis of High False Alarm in SVD Based Watermarking and Improved Algorithm
Wei Zhi-hui · Journal of Nanjing University of Science and Technology · 2010
The problem of high false alarm for a class of singular value decomposition(SVD) based image watermarking algorithms is investigated and the corresponding essential reasons are discussed.The intrinsic reasons that cause the high false alarm problem are: the basis space of SVD is relative to image content;there is no one-to-one correspondence between singular value vector and image;singular value vectors have no information of the structure of image,thus the most important reason is a result of false conception to insert watermark singular value vectors without using the structure information of watermark.An improved image watermarking algorithm is proposed combining the block-SVD and discrete cosine transform(DCT) decomposition.The DCT coefficients of watermark image are embedded into the singular value vectors of host image,and the improved algorithm can overcome the high false alarm problem which exists in the classical SVD based algorithms and also it has good robustness.Experimental results prove the effectiveness of the theoretical analysis and the improved algorithm.