Multiple Description Coding : proposed methods and video application
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Authors
Moradi, Saeed
Date
2007-08-29T14:06:52Z
Type
thesis
Language
eng
Keyword
Multiple Description Coding , Quantization , Video
Alternative Title
Abstract
Multiple description coding (MDC) has received a lot of attention recently,
and has been studied widely and extended to many demanding applications such
as speech and video. MDC is a coding technique that generates correlated
descriptions of the source stream for transmitting over a diversity system
with several channels. The objective of this diversity system is to overcome
channel impairments and provide more reliability. In the context of lossy
source coding and quantization, a multiple description quantization system
usually consists of multiple channels, side encoders to quantize the source
samples and send over different channels, and side and central decoders to
reconstruct the source.
We propose two multiple description quantization schemes in
order to design the codebooks and partitions of side and central quantizers
of a multiple description system with two channels. The applied framework
originated in the multiple description quantization via Gram-Schmidt
orthogonalization approach. The basic idea of our proposed schemes is to
minimize a Lagrangian cost function by an iterative technique which jointly
designs side codebooks and partitions. Our proposed methods perform very
closely to the optimum MD quantizer with considerably less complexity.
We also propose a multiple description video coding technique motivated by
human visual perception. We employ two simple parameters as a measure of the
perceptual tolerance of discrete cosine transform (DCT) blocks against
visual distortion. We duplicate the essential information such as motion
vectors and some low-frequency DCT coefficients of prediction errors into
each description, and split the remaining high-frequency DCT coefficients
according to the calculated perceptual tolerance parameter. Our proposed
technique has very low complexity and achieves superior performance compared
to other similar techniques which do not consider perceptual distortion in
the design problem.
Description
Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2007-08-19 03:33:10.451
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