Wavelet Based Lattice Vector Quantization Scheme For Multiple Description System

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Date
2010-08
Authors
Infall, Syafalni
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Abstract
Recent years have witnessed the increase in demand for fast, efficient, and high quality multimedia communication applications over the wired and wireless networks. The constraint in bandwidth has paved the researchers to embark their efforts in finding the efficient compression techniques for image and video. Data transmission via network communication system with a single channel is always likely to fail because of noise and interference which lower the system performance. In order to increase the robustness and therefore offering high performance, multiple descriptions coding (MDC) has been proposed. MDC produces several separate descriptions, while decoding individual description can reproduce the source with certain accuracy. MDC related works incorporates compression schemes especially vector quantization (VQ) and lattice VQ techniques. In this thesis, various A2 LVQ quantizing techniques are introduced and the proofs are simulated in personal computer as well as using mathematical derivations. Since the Az LVQ has low performance in quantization, a new algorithm for multistage Az LVQ (MAzLVQ) is introduced to improve the performance. The hybrid multistage LVQ quantizers (Hy-MLVQ) techniques are also presented. The new schemes use the combination of two lattice types. A unique method to calculate and construct the Az lattice structure is presented using the triangle number and square numbers. In this development, mathematical and geometrical expressions are used to provide better understanding of the construction process. Then wavelet based image coding using the various LVQ techniques are presented. In this work, the MA2LVQ is used to encode the wavelet transformed image or subbands with the help of the proposed adaptive normalization technique where significant improvement in performance is noticed. Wavelet based image coding also utilizes the new hybrid multiple bitplane-MA2LVQ (HBM-LVQ). The HBM-LVQ utilizes three side decoders. The scheme also proposes a perfect estimation decoder and operates at very low bit rate. The third part of this thesis is the hardware implementation of the ordinary A2 architecture design. Moreover, the new low complexity A2 LVQ hardware architecture is also proposed. Then, the MA2LVQ hardware architecture is developed using severalA2 LVQ quantizers that are arranged consecutively. The performance of synthesizable MA2LVQ also is conducted using RTL and gate level simulations. Finally the MA2LVQ is implemented using the DE2 FPGA (Cyclone II) and displays the output using the VGA controller in LCD monitor. Experimental results show that the proposed MA2LVQ and Hy-MLVQ quantizers allow reduction of quantization distortion due to the increment of lattice point density in the subsequent sub lattice or quantizer. The adaptive normalization technique for wavelet based image coding using MA2LVQ quantizer also offers significant improvement in performance. Moreover, the HBM-LVQ can reach very low bit rate (below 0.2 bpp) and exhibits good performance in all side decoders. The synthesizable low complexity A2 LVQ architecture performs well up to 35.97 nanoseconds (ns). Finally, the implementation of MA2LVQ shows that by using the low complexity A2 reduces the use of logic and register elements up to 47% as compared to the ordinary A2 LVQ architecture.
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Electrical and Electronic Engineering , Communication
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