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URN etd-0204108-145643 Statistics This thesis had been viewed 2814 times. Download 1326 times. Author Zhi-Jie Chen Author's Email Address firstname.lastname@example.org Department Electro-Optical Engineering Year 2007 Semester 1 Degree Master Type of Document Master's Thesis Language English Page Count 57 Title Rigorous coupled-wave analysis based on image coding application Keyword coding transform RCWA RCWA transform coding Abstract Nonlinear transform plays more and more important in the coding field. This approach would provide higher compression coefficients. The goal of this thesis is what we use optical method for image coding based on rigorous coupled wave (RCW) theory as the forward transform. We treat the gray values of the image as the depth of a surface relief grating, where the region is modulated. Based on a series of fundamental assumptions and determining the boundary conditions, the modulating of the amplitude of the electric field is obtained. We can also get the coefficients of the electric fields. We hope to introduce the vector quantization (VQ) algorithm to cluster the coefficients in order to reduce the information and obtain high compression ratio. Experiments results show that for small size picture, at medium bit rates, PSNR is gain about 4 dB. And for large picture, PSNR goes up quicker and have good compression ratio. For 512 512 picture, when bite rates per pixel is 0.0625, PNSR cans reach 35 dB higher. For human vision, the quality of details of RCWA is better than JPEG 2000. Advisor Committee Mu-Shiang Wu - advisor
Nai-Yuan Chang - co-chair
Tsung-Hui Tsai - co-chair
Files Date of Defense 2008-01-29 Date of Submission 2008-02-04