37284906
Novel video signal processor with VLIW-controlled SIMD architecture
In this paper, we present a novel video signal processor (VSP) architecture, named VS-VSP, which combines the very long instruction word (VLIW) control with the single instruction multiple data (SIMD) processing technology. The SIMD architecture provides high performance for the computation-intensive tasks, and the VLIW control introduces satisfactory flexibility to the whole system. In addition, a hierarchical memory organization is employed in VS-VSP to tackle the high data-bandwidth requirements in the video signal processing application. The proposed VS-VSP architecture can be exploited for implementing a variety of video coding algorithms efficiently.
9503765
Unequal-arm adaptive rood pattern search for fast block-matching motion estimation in the JVT/H.26L
The adaptive rood pattern search (ARPS) algorithm proposed by Nie and Ma (2002) has shown two to three times of search speed-up improvement over that of diamond search (DS) based on the MPEG-4 verification model encoding platform. In this paper, first we have shown that the distribution of motion vectors bears a rood shape. An improved ARPS algorithm, called ARPS-3 or unequal-arm ARPS, is then proposed and experimented on the JVT/H.26L JM encoding platform. Due to complex modes and multiframe prediction, a new normalized computational cost metrics is also proposed for objectively measuring the computational gain or search speed-up. Experimental results show that ARPS-3 has achieved superb performance on many accounts while maintaining fairly close rate-distortion performance compared with that of the full search. It also outperforms its predecessors, ARPS and ARPS-2 (or equal-arm ARPS).
14032639
Sliding-window packetization for unequal loss protection based multiple description coding
Unequal loss protection (ULP) for transmitting embedded bitstream over packet erasure networks has been extensively studied. However, most of the existing works focused on rate-distortion optimization of individual encoding unit, e.g., a group of pictures (GOP), which may lead to noticeable video quality variations due to varying channel conditions. In this paper, a novel sliding-window packetization scheme is proposed, which combat bursty packet loss through GOP interleaving. Two levels of rate allocation are introduced: intra-GOP rate allocation minimizes the distortion of individual GOP, and provides hybrid FEC/retransmission packet loss recovery; while inter-GOP rate allocation intends to reduce video quality fluctuations by adaptively allocating bandwidth according to video signal characteristics. Through this way, more consistent video quality can be achieved under various packet loss probability, as verified by our experimental results.
2488876
Tri-state median filter for image denoising
In this work, a novel nonlinear filter, called tri-state median (TSM) filter, is proposed for preserving image details while effectively suppressing impulse noise. We incorporate the standard median (SM) filter and the center weighted median (CWM) filter into a noise detection framework to determine whether a pixel is corrupted, before applying filtering unconditionally. Extensive simulation results demonstrate that the proposed filter consistently outperforms other median filters by balancing the tradeoff between noise reduction and detail preservation.
9933284
A MCMC approach for Bayesian super-resolution image reconstruction
In this paper, we consider the super-resolution image reconstruction problem. We propose a Markov chain Monte Carlo (MCMC) approach to find the maximum a posterior probability (MAP) estimation of the unknown high-resolution image. Firstly, Gaussian Markov random field (GMRF) is exploited for modeling the prior probability distribution of the unknown high-resolution image. Then, a MCMC technique (in particular, the Gibbs sampler) is introduced to generate samples from the posterior probability distribution to compute the MAP estimation of the unknown high-resolution image, which is obtained as the mean of the samples. Moreover, we derive a bound on the convergence time of the proposed MCMC approach. Finally, the experimental results are presented to verify the superior performance of the proposed approach and the validity of the proposed bound.
1533691
Generalized optimum dynamic bit allocation scheme for source compression
Dynamic bit allocation directly impacts the overall coding performance in block transform (e.g., DCT, Hadamard, etc.) coding, subband coding, and wavelet coding. In very low bit rate coding (such as the evolving MPEG-4 standard), additional factors impacting the bit allocation process need to be identified and properly exploited to achieve optimal coding performance. In the paper, a generalized optimum dynamic bit allocation algorithm is presented. The algorithm is based on the Shannon rate-distortion bound and a weighted distortion criterion using a Lagrange multiplier optimization technique. The results look promising for applications in real-time multimedia communications.<<ETX>>
5064603
The ascending star subgraph decomposition of some star forests