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Hot topic:Review of the current and future technologies for video compression

Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第1期11卷 1-13页

作者： Lu YU Jian-peng WANG Institute of Information and Communication Engineering Zhejiang University Hangzhou 310027 China Key Laboratory of lntegrated lnformation Network Technology of Zhejiang Province Hangzhou 310027 China

Many important developments in video compression technologies have occurred during the past two decades. The block-based discrete cosine transform with motion compensation hybrid coding scheme has been widely employed by most available video coding standards, notably the ITU-T H.26x and ISO/IEC MPEG-x families and video part of China audio video coding standard (AVS). The objective of this paper is to provide a review of the developments of the four basic building blocks of hybrid coding scheme, namely predictive coding, transform coding, quantization and entropy coding, and give theoretical analyses and summaries of the technological advancements. We further analyze the development trends and perspectives of video com- pression, highlighting problems and research directions.

关键词： Video compression predictive coding Transform coding Quantization, Entropy coding Theoretical analysis

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Motion compensation for block-based lossless video coding using lattice-based binning

Motion compensation for block-based lossless video coding us...

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IEEE International Symposium on Circuits and Systems (ISCAS)

作者： Mortuza Ali Manzur Murshed Gippsland School of Information Technology Monash University VIC Australia

A block-based lossless video coding scheme using the notion of binning has been proposed in. To further improve the compression and reduce the complexity, in this paper we investigate the impact of two sub-optimal motion search algorithms on the performance of this lattice-based scheme. While one of the algorithm tries avoiding motion vectors, the other tries to reduce complexity. Our experimental results have demonstrated that the loss due to sub-optimal motion search outweighs the gain when motion vectors are avoided. However, experimental results have shown that there is negligible performance loss when low-complexity sub-optimal three step search is used.

关键词： Motion compensation Video coding Video compression Image coding predictive coding Information technology Performance loss Bandwidth Costs Biomedical imaging

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OPTIMAL DELAYED DEcoding OF predictiveLY ENCODED SOURCES

OPTIMAL DELAYED DECODING OF PREDICTIVELY ENCODED SOURCES

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IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Vinay Melkote Kenneth Rose Department of Electrical and Computer Engineering University of California Santa Barbara CA 93106

ISBN: (纸本)9781424442959

predictive coding eliminates redundancy due to correlations between the current and past signal samples, so that only the innovation, or prediction residual, needs to be encoded. However, the decoder may, in principle, also exploit correlations with future samples. Prior decoder enhancement work mainly applied a non-causal filter to smooth the regular decoder reconstruction. In this work we broaden the scope to pose the problem: Given an allowed decoding delay, what is the optimal decoding algorithm for predictively encoded sources? To exploit all information available to the decoder, the proposed algorithm recursively estimates conditional probability densities, given both past and available future information, and computes the optimal reconstruction via conditional expectation. We further derive a near-optimal low complexity approximation to the optimal decoder, which employs a time-invariant lookup table or codebook approach. Simulations indicate that the latter method closely approximates the optimal delayed decoder, and that both considerably outperform the competition.

关键词： predictive coding smoothing delayed decoding DPCM recursive estimate prediction coding differential pulse code modulation decoders smoothing DEcoding conditional expectation

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A New predictive Image Compression Scheme Using Histogram Analysis and Pattern Matching

A New Predictive Image Compression Scheme Using Histogram An...

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International Conference on Computer Engineering and Applications (ICCEA)

作者： Farhad Keissarian University of Wollongong UAE

ISBN: (纸本)9781424460793

In this paper, we introduce a new predictive image compression scheme that compresses an image by a set of parameters computed for individual blocks of different types. These parameters include the average and difference of the representative intensities of an image block, together with the index of a pattern associated with the block visual activity. The block representative gray values are computed through a histogram analysis of the block residuals and a pattern matching technique is employed to find the best match for the block bit-pattern from a pre-defined pattern book. To further reduce the bit rate, a predictive technique selectively predicts the parameters based on the corresponding values in the neighboring blocks. The simulation results confirm that the proposed technique can provide a high compression ratio with acceptable image quality of the compressed images.

关键词： Image coding Histograms Image analysis Pattern analysis Pattern matching predictive coding Bit rate Vector quantization Image quality Decoding

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Information Flows in Video coding

Information Flows in Video Coding

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Data Compression Conference (DCC)

作者： Jia Wang Xiaolin Wu Department of Electronic Engineering Shanghai Jiaotong University Shanghai China Department of Electrical & Computer Engineering McMaster University Canada

ISBN: (纸本)9781424464258;9780769539942

We study information theoretical performance of common video coding methodologies at the frame level. Via an abstraction of consecutive video frames as correlated random variables, many existing video coding techniques, including the baseline of MPEG-x and H.26x, the scalable coding and the distributed video coding, can have corresponding information theoretical models. The theoretical achievable rate distortion regions have been completely solved for some systems while for others remain open. We show that the achievable rate region of sequential coding equals to that of predictive coding for Markov sources. We give a theoretical analysis of the coding efficiency of B frames in the popular hybrid video coding architecture, bringing new understanding of the current practice. We also find that distributed sequential video coding generally incurs a performance loss if the source is not Markov.

关键词： Video coding Random variables predictive coding Decoding Data engineering Rate-distortion Network coding Data compression Data flow computing Performance loss

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Grassmannian predictive frequency domain compression for limited feedback beamforming

Grassmannian predictive frequency domain compression for lim...

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Information Theory and Applications Workshop, ITA

作者： Takao Inoue Robert W. Heath National Instruments Austin TX USA Department of Electrical and Computer Engineering University of Texas Austin Austin TX USA

Frequency domain channel correlation can be exploited to reduce feedback in limited feedback beamforming multiple-input multiple-output orthogonal frequency division multiplexing wireless systems. Prior methods rely on downsampling, interpolation, or clustering the channel state information in the frequency domain. The resulting compressed samples are quantized using one-shot quantization on the Grassmann manifold. The resolution, unfortunately, is limited. We propose a new frequency domain compression technique to obtain high resolution channel state information. The key idea is to use predictive coding on the Grassmann manifold, exploiting the correlation between adjacent subcarriers.

关键词： Frequency domain analysis Feedback Array signal processing Quantization Transmitters MIMO OFDM Interpolation Channel state information predictive coding

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predictive coding of Lossless Data Compression: A New Particle Dynamics Model

Predictive Coding of Lossless Data Compression: A New Partic...

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IEEE International Symposium on Industrial Electronics (ISIE)

作者： Dianxun Shuai Liangjun Huang Ping Zhang Department of Computer Science and Engineering East China University of Science and Technology Shanghai China Institute of Intelligent Information Proc. Xidian University Xi'an China

A new particle dynamics model (PDM) is proposed for the prediction-based lossless data compression. The structure, algorithm and properties of PDM used to generate the desired predictive coding are discussed. The proposed PDM approach has advantages in terms of parallelism, scalability, and easy hardware implementation over other sequential lossless compression methods.

关键词： predictive coding Data compression predictive models Image coding Wavelet transforms Multimedia databases Image reconstruction Parallel processing Scalability Hardware

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Cortical circuits for perceptual inference

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NEURAL NETWORKS 2009年第8期22卷 1093-1104页

作者： Friston, Karl J. Kiebel, Stefan UCL Wellcome Trust Ctr Neuroimaging Inst Neurol London WC1N 3BG England

This paper assumes that cortical circuits have evolved to enable inference about the causes of sensory input received by the brain. This provides a principled specification of what neural circuits have to achieve. Here, we attempt to address how the brain makes inferences by casting inference as an optimisation problem. We look at how the ensuing recognition dynamics Could be Supported by directed connections and message-passing among neuronal populations, given our knowledge of intrinsic and extrinsic neuronal connections. We assume that the brain models the world as a dynamic system, which imposes causal structure on the sensorium. Perception is equated with the optimisation or inversion of this internal model, to explain sensory input. Given a model of how sensory data are generated, we use a generic variational approach to model inversion to furnish equations that prescribe recognition: i.e., the dynamics of neuronal activity that represents the causes of sensory input. Here, we focus on a model whose hierarchical and dynamical structure enables Simulated brains to recognise and predict sequences of sensory states. We first review these models and their inversion under a variational free-energy formulation. We then show that the brain has the necessary infrastructure to implement this inversion and present stimulations using synthetic birds that generate and recognise birdsongs. (C) 2009 Elsevier Ltd. All rights reserved.

关键词： Generative models predictive coding Hierarchical Dynamic Nonlinear Circuits Variational Birdsong Free-energy

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Reversible data hiding of a VQ index table based on referred counts

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JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2009年第6期20卷 399-407页

作者： Yang, Cheng-Hsing Lin, Yi-Cheng Natl Pingtung Univ Educ Dept Comp Sci Pingtung 900 Taiwan

This paper presents a new reversible VQ-based hiding scheme that can recover the original VQ compressed codes after data extraction. Our scheme sorts a VQ codebook using the referred counts. The VQ codebook is then divided into 2(B) clusters and half of these clusters are used to embed secret data, in which B denotes the size of the secret data embedded into each VQ index. Compared to Chang et al.'s scheme, which divides a sorted VQ codebook into 2(B-1) x 3 clusters and uses the front one-third clusters to embed secret data, our method can embed more data. Moreover, indicator, index exchanging, and side-match prediction schemes are proposed to further improve our scheme. Under the same sorted VQ codebook, the experimental results demonstrate that our data hiding algorithm has higher capacities and better compression rates. (C) 2009 Elsevier Inc. All rights reserved.

关键词： Data hiding Reversible embedding Vector quantization Codebook clustering Lossless compression Steganography Side-match predictive coding

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Forward and backward connections in the brain: A DCM study of functional asymmetries

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NEUROIMAGE 2009年第2期45卷 453-462页

作者： Chen, C. C. Henson, R. N. Stephan, K. E. Kilner, J. M. Friston, K. J. UCL Inst Neurol Wellcome Trust Ctr Neuroimaging London WC1N 3BG England MRC Cognit & Brain Sci Unit Cambridge England Univ Zurich Lab Social & Neural Syst Res Inst Empir Res Econ CH-8006 Zurich Switzerland

In this paper, we provide evidence for functional asymmetries in forward and backward connections that de. ne hierarchical architectures in the brain. We exploit the fact that modulatory or nonlinear influences of one neuronal system on another (i.e., effective connectivity) entail coupling between different frequencies. Functional asymmetry in forward and backward connections was addressed by comparing dynamic causal models of MEG responses induced by visual processing of normal and scrambled faces. We compared models with and without nonlinear (between-frequency) coupling in both forward and backward connections. Bayesian model comparison indicated that the best model had nonlinear forward and backward connections. Using the best model we then quantified frequency-specific causal influences mediating observed spectral responses. We found a striking asymmetry between forward and backward connections;in which high (gamma) frequencies in higher cortical areas suppressed low (alpha) frequencies in lower areas. This suppression was significantly greater than the homologous coupling in the forward connections. Furthermore, exactly the asymmetry was observed when we examined face-selective coupling (i.e., coupling under faces minus scrambled faces). These results highlight the importance of nonlinear coupling among brain regions and point to a functional asymmetry between forward and backward connections in the human brain that is consistent with anatomical and physiological evidence from animal studies. This asymmetry is also consistent with functional architectures implied by theories of perceptual inference in the brain, based on hierarchical generative models. (c) 2008 Elsevier Inc. All rights reserved.

关键词： Nonlinear coupling Neuronal dynamics Induced responses Dynamic causal modelling Spectral responses Backward connection Recurrent connection Reentrant dynamics predictive coding

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