Upul Samarawickrama

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A new multiple description coding paradigm is proposed by combining the time-domain lapped transform, block level source splitting, linear prediction, and prediction residual encoding. The method provides effective redundancy control and fully utilizes the source correlation. The joint optimization of all system components and the asymptotic performance(More)
A low complexity M-channel multiple description coding scheme is developed in this paper, in which each description carries one subset of the input with a higher bit rate and the rest with a lower bit rate. The lower-rate codings in different descriptions are designed to be mutually refinable using staggered scalar quantizers. For correlated sources, a(More)
In this paper, two multiple description coding schemes are developed, based on prediction-induced randomly offset quantizers and unequal-deadzone-induced near-uniformly offset quantizers, respectively. In both schemes, each description encodes one source subset with a small quantization stepsize, and other subsets are predictively coded with a large(More)
A low complexity multiple description (MD) coding method is proposed to generate M descriptions. Consider the MD coding of a stationary correlated source. We first fictitiously partition the source into sample blocks of size M, i.e., M polyphases. Each description encodes all input samples, but with a variable bit rate that depends on the indices of the(More)
In this paper we consider the transmission of multiple descriptions over a channel where there are random errors in addition to erasures. We present a list Viterbi algorithm (LVA) based joint decoding scheme which exploits the correlation introduced by the multiple description encoding to improve the signal to noise ratio at the receiver. The scheme is(More)
A two-stage multiple description predictive coding technique is proposed. A predictive encoder is used in the first stage of each description. The two encoders are designed to create staggered quantizers for the input, which allow further refinement of the joint reconstruction in the second stage. Theoretical analysis and simulation results show that this(More)
A new multiple description image coding paradigm is presented in this paper by combining the lapped transform, block level source splitting, inter-description prediction, and coding of the prediction residual. Jointly optimal designs of all system components are discussed. Compared with the best multiple description image coding algorithm in the literature,(More)