An image watermarking technique using pyramid transform
MULTIMEDIA '01 Proceedings of the ninth ACM international conference on Multimedia
Nonlinear Harten's multiresolution on the quincunx pyramid
Journal of Computational and Applied Mathematics
Cell-average nonlinear multiresolution on the quincunx pyramid
SSIP'05 Proceedings of the 5th WSEAS international conference on Signal, speech and image processing
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A nonexpansive pyramidal decomposition is proposed for low-complexity image coding. The image is decomposed through a nonlinear filterbank into low- and highpass signals and the recursion of the filterbank over the lowpass signal generates a pyramid resembling that of the octave wavelet transform. The structure itself guarantees perfect reconstruction and we have chosen nonlinear filters for performance reasons. The transformed samples are grouped into square blocks and used to replace the discrete cosine transform (DCT) in the Joint Photographic Expert Group (JPEG) coder. The proposed coder has some advantages over the DCT-based JPEG: computation is greatly reduced, image edges are better encoded, blocking is eliminated, and it allows lossless coding