TITLE:
New Video Watermark Scheme Resistant to Super Strong Cropping Attacks
AUTHORS:
Ming Tong, Tao Chen, Wei Zhang, Linna Dong
KEYWORDS:
Digital Watermarking; Cropping Attack; Geometric Attacks; Nonnegative Matrix Factorization (NMF); Sparseness Constrain
JOURNAL NAME:
Journal of Information Security,
Vol.3 No.2,
April
26,
2012
ABSTRACT: Firstly, the nonnegative matrix factorization with sparseness constraints on parts of the basis matrix (NMFSCPBM) method is proposed in this paper. Secondly, the encrypted watermark is embedded into the big coefficients of the basis matrix that the host video is decomposed into by NMFSCPBM. At the same time, the watermark embedding strength is adaptively adjusted by the video motion characteristic coefficients extracted by NMFSCPBM method. On watermark detection, as long as the residual video contains the numbers of the least remaining sub-blocks, the complete basis matrix can be completely recovered through the decomposition of the nonnegative matrix of the least remaining sub-blocks in residual videos by NMFSCPBM, and then the complete watermark can be extracted. The experimental results show that the average intensity resistant to the various regular cropping of this scheme is up to 95.97% and that the average intensity resistant to the various irregular cropping of this scheme is up to 95.55%. The bit correct rate (BCR) values of the extracted watermark are always 100% under all of the above situations. It is proved that the watermark extraction is not limited by the cropping position and type in this scheme. Compared with other similar methods, the performance of resisting strong cropping is improved greatly.