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—Recent dictionary training algorithms for sparse representation like K-SVD, MOD, and their variation are reminiscent of K-means clustering, and this letter investigates such algorithms from that viewpoint. It shows: though K-SVD is sequential like K-means, it fails to simplify to K-means by destroying the structure in the sparse coefficients. In contrast,(More)
A watermarking method b ased on variable dimension vector quantization for hiding information in im-a g e s i s p r esented in this paper. Watermark bits are embedded in the dimension information of the variable dimension reconstruction blocks of the cover or input image. Watermark extraction for oblivious wa-termarking is carried out by identifying the(More)
The eigenstructure based characterization of M-channel FIR PR filterbanks of [1] is extended here to the linear phase case. Some results relating to linear phase filterbanks is derived by finding appropriate restrictions on the eigenstructure of the analysis polyphase matrix. Consequently a complete and minimal characterization for such filterbanks with all(More)
The use of a suitable perceptual model is necessary to minimize the visual distortion in the marked images, because minor modification to the pixels can be perceptible since the pixels are either black or white. In this paper, a new perceptual model is proposed for binary images that is useful for data hiding applications. In our model, the distortion that(More)