Zhihua He

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—As adoption of the newly standardized H.264 becomes increasingly more widespread, efforts must be made to transcode video from earlier standards, such as MPEG-2, to the H.264 format. One aspect of transcoding is the conversion from the discrete cosine transform (DCT) used in MPEG-2 to the integer-based DCT of H.264, the integer cosine transform. By(More)
Two statistical models for color texture retrieval based on a hidden Markov model (HMM) in the contourlet domain are described in this paper. Through a contourlet transformation , each color component of an image is decomposed into a set of directional subbands with texture details captured in different orientations. By exploiting inter-scale dependencies(More)
Due to their abilities to succinctly capture features at different scales and directions, wavelet-based decomposition or representation methods have found wide use in image analysis, restoration, and compression. While there has been a drive to increase the representation ability of these methods via directional filters or elongated basis functions, they(More)
Variants of the discrete cosine transform (DCT) have been selected for different image/video compression standards, and fast conversion algorithms between these transforms are needed. In this paper, conversion between an 8 × 8 DCT block, used in MPEG-2, and its corresponding 4 × 4 integer DCT blocks, used in H.264, is studied. By investigating the structure(More)