Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Implementational Aspects of the Contourlet Filter Bank and Application in Image Coding | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 373487 18 pages doi 2008 373487 Research Article Implementational Aspects of the Contourlet Filter Bank and Application in Image Coding Truong T. Nguyen 1 Yilong Liu 2 Herve Chauris 1 and Soontorn Oraintara2 1 Geophysical Research Center Paris School of Mines 35 Rue Saint-Honoré 77305 Fontainebleau France 2 Department of Electrical Engineering University of Texas at Arlington 416 Yates St. Arlington Texas 76019 USA Correspondence should be addressed to Truong T. Nguyen Received 29 March 2008 Accepted 10 October 2008 Recommended by Wilfried Philips This paper analyzed the implementation aspects of the contourlet filter bank or the pyramidal directional filter bank PDFB and considered its application in image coding. First details of the binary tree-structured directional filter bank DFB are presented including a modification to minimize the phase delay factor and necessary steps for handling rectangular images. The PDFB is viewed as an overcomplete filter bank and the directional filters are expressed in terms of polyphase components of the pyramidal filter bank and the conventional DFB. The aliasing effect of the conventional DFB and the Laplacian pyramid to the directional filters is then considered and the conditions for reducing this effect are presented. The new filters obtained by redesigning the PDFBs satisfying these requirements have much better frequency responses. A hybrid multiscale filter bank consisting of the PDFB at higher scales and the traditional maximally decimated wavelet filter bank at lower scales is constructed to provide a sparse image representation. A novel embedded image coding system based on the image decomposition and a morphological dilation algorithm is then presented. The coding algorithm efficiently clusters the significant coefficients using progressive morphological operations. Context models for .
