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Data Compression Conference (DCC)

作者： Emrah Akyol Kenneth Rose University of California Santa Barbara CA USA

This paper is concerned with transform coding of correlated sources in conjunction with variable rate quantization at high resolution. The approach builds on our prior work on optimality conditions for transform coding in the point-to-point setting. The first contribution involves transform coding with decoder side information. In this setting, side information is only available to the decoder, whereas the encoder knows the joint statistics. The necessary and sufficient condition for optimality of a unitary transform in the side information setting is derived, namely, such transform minimizes a conditional divergence-based measure of inter-dependence of the transform coefficients, given the side information. This optimality result subsumes prior, known results that were restricted to the Gaussian case, where the conditional Karhunen-Loeve transform is optimal. The second contribution involves distributed transform coding, where two correlated sources are to be transform coded separately, but decoded jointly. The necessary and sufficient condition for optimality of unitary transforms in the distributed coding setting is derived. It is then specialized to produce closed form optimal transforms for specific source densities, including the case of jointly Gaussian sources.

关键词： transforms transform coding Vectors Encoding Decoding Quantization Covariance matrix

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DCT/DST ALTERNATE-transform IMAGE-coding

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IEEE TRANSACTIONS ON COMMUNICATIONS 1990年第1期38卷 94-101页

作者： ROSE, K HEIMAN, A DINSTEIN, IH BEN GURION UNIV NEGEV DEPT ELECT & COMP ENGNIL-84105 BEER SHEVAISRAEL TADRIAN LTD DIV COMMUNDIGITAL EQUIPMENT PLANTHOLON 58102ISRAEL

An image coding method for low bit rates is proposed. It is based on alternate use of the discrete cosine transform (DCT) and the discrete sine transform (DST) on image blocks. This procedure achieves the removal of redundancies in the correlation between neighboring blocks as well as the preservation of continuity across the block boundaries. An outline of the mathematical justification of the method, assuming a certain first-order Gauss-Markov model, is given. The resulting coding method is then adapted to nonstationary real images by locally adapting the model parameters and improving the block classification technique. Simulation results are shown and compared with the performance of related previous methods, namely adaptive DCT and fast Karhunen-Loeve transform (FKLT).< >

关键词： Discrete cosine transforms Image coding Karhunen-Loeve transforms Gaussian processes Bit rate Redundancy transform coding Mathematical analysis Discrete transforms Mathematical model

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Comparison of some efficient techniques for transform coding of images with reduced blocking effects

Comparison of some efficient techniques for transform coding...

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Mediterranean Electrotechnical Conference (MELECON)

作者： M. Popovic D. Curapov Fac. of Electr. Eng. Belgrade Univ. Yugoslavia Faculty of Electrical Engineering University of Belgrade Belgrade Serbia

transform coding techniques for image transmission are examined in detail and compared to the DCT (discrete cosine transform) under the same conditions, e.g. data rate, type of quantization of coefficients, number of operations needed, suitability for real-time execution, and quality of the received image. The quality is measured by objective (normalized mean square error) and subjective criteria. The images used in the experiments represent different situations which may arise in practice (buildings, head and shoulder, aerial images). These investigations show that the LOT (lapped orthogonal transform) has some advantages at data rates about 0.5 b/pixel, although DCT is better regarding computing speed and ringing effects.< >

关键词： transform coding Discrete cosine transforms Discrete transforms Image storage Hardware Image communication Ambient intelligence Quantization Head Very large scale integration

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Improved MPEG-4 visual texture coding using double transform coding

Improved MPEG-4 visual texture coding using double transform...

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IEEE International Symposium on Circuits and Systems (ISCAS)

作者： Chung-Neng Wang Tihao Chiang Chi-Min Liu Hung-Ju Lee Currently a Professor of the Department and Institute of Computer Science and Information Engineering NCTU Taiwan Currently an Assistant Professor of the Department and Institute of Electronics Engineermg NCTU Taiwan Mediasoft Laboratory Sony US Research Laboratories San Jose USA

ISBN: (纸本)0780366859

MPEG-4 Visual Texture coding (VTC) was recently adopted as an image coding technique using a wavelet-based approach. For images with significant texture and sharp contrast, MPEG-4 VTC spreads the signal energy over several wavelet trees. To improve the coding efficiency of zerotree entropy coding, we propose a double transformation coding (DTC) approach. The wavelet trees are reorganized as a sequence of wavelet blocks, which are categorized into four groups where the similarity among the blocks within a group is increased. For each class, we use an adaptive Karhunen Loeve transform (KLT) bases to predict the quantized AC coefficients of the same class. The classification process is based on the variances of the quantized DC coefficients considering the spatial orientation. Thus, the classification information can be computed at the decoder. At the same time, the property of continuous scalability is maintained using the new approach. For the same bitrate we found that the DTC achieved a coding gain over MPEG-4 VTC by about 0.5-1.0 dB in PSNR.

关键词： MPEG 4 Standard transform coding Frequency Discrete wavelet transforms Laboratories Image coding Wavelet coefficients Entropy coding Wavelet transforms Decoding

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Canonical coordinates are the right coordinate system for transform coding of noisy sources

Canonical coordinates are the right coordinate system for tr...

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IEEE/SP Workshop on Statistical Signal Processing (SSP)

作者： P.J. Schreier L.L. Scharf Tianjian Hu S.D. Voran Dept. of ECE University of Colorado Boulder USA Dept's of ECE and Statistics Colorado State University Ft. Collins Institute for Telecommunication Sciences Boulder CO

Historically, transform coding of noisy sources has been performed by first estimating the message and then quantizing this estimate. We show that it is also optimum to first transform the noisy observations into canonical coordinates, quantize, apply a Wiener filter in this coordinate system, and then transform the result back to the original coordinates. Canonical coordinates are uncorrelated, and quantizing and Wiener filtering are applied to each component independently. Optimality of this approach can be proved assuming additive white quantization noise. Half canonical coordinates minimize the mean-squared error by minimizing the trace of the error covariance matrix and full canonical coordinates maximize information rate by minimizing the determinant of the error covariance matrix.

关键词： transform coding Quantization Electronic mail Covariance matrix Wiener filter Additive white noise State estimation Information rates Statistics Colored noise

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Hierarchical transform coding using NURBS approximation

Hierarchical transform coding using NURBS approximation

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International Symposium on Electronics in Marine (ELMAR)

作者： Jaroslav Polec Sandra Ondrusova Kvetoslava Kotuliakova Natalia Helesova Tatiana Karlubikova Department of Telecommuniactions Slovak University of Technology Slovakia

A scheme of utilizing shape independent basis functions for the hierarchical multiresolution image compression is shown. First, the input image is segmented and its segmentspsila boundaries are NURBS approximated, thus achieving an image mask. Second, this image mask and the image are used as the input of the tree-level hierarchical encoder. Hierarchical encoder subsamples image and image mask and encodes them shape independently. Another compression mode is, hence, successfully introduced for shape independent transform coding.

关键词： transform coding Spline Surface topography Surface reconstruction Image segmentation Decoding Shape Image coding Image resolution Streaming media

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Optimal transform coding of Gaussian mixtures for joint classification/reconstruction

Optimal transform coding of Gaussian mixtures for joint clas...

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Data Compression Conference (DCC)

作者： Soumya Jana P. Moulin Coordinate Science Laboratory Beckman Institute University of Illinois Urbana-Champaign Urbana-Champaign IL USA

In a variety of applications, classification systems operate on compressed signals. The design of optimal transform coders optimizing a joint classification/reconstruction criterion was explored, where classification accuracy is measured using the Chernoff bound on probability of misclassification and reconstruction quality is measured using mean-squared error (MSE) distortion. Under a high-rate assumption, local optimality properties of the Karhunen-Loeve transform (KLT) for a certain class of Gaussian mixtures under a joint classification/MSE measure was shown. Analytical expressions for optimal bit-allocation were derived. This generalizes classical optimality properties of the KLT for Gaussian sources under the MSE criterion.

关键词： transform coding Image reconstruction Karhunen-Loeve transforms Design optimization Distortion measurement Image coding Compression algorithms Data compression Decorrelation Bit rate

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Multiresolution vector transform coding for video compression

Multiresolution vector transform coding for video compressio...

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1993 IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： B. DeCleene H. Sorensen Department of Electrical Engineering University of Pennsylvania Philadelphia PA USA

A novel image and video compression algorithm based on block and vector transformations used in a multiresolution approach is described. The algorithm is shown to yield substantial compression gains over regular block coding with only a small increase in the computational load. In particular, the transform efficiency on a first-order Markov process is demonstrated to exceed that of a block transformation and approach the efficiency of the full transformation as the correlation factor approaches unity. Experiments with real video data also illustrate the compression gains for a variety of vector transformations, including vector DCT (discrete cosine transform) and vector Hadamard. Combined with an inherent robustness to vector loss, the proposed transformation is very well suited for applications requiring low bit rates over a degraded channel such as packet video during network congestion.< >

关键词： transform coding Video compression Discrete cosine transforms Image resolution Image coding Block codes Discrete transforms Markov processes Robustness Bit rate

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A transform coding chip set for image compression

A transform coding chip set for image compression

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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： I. Shah O. Akiwumi-Assani B. Johnson Philips Laboratories North American Philips Corporation Briarcliff Manor NY USA

Two application-specific integrated circuits (ASICs) were designed to perform hierarchical transformation (S-transform processor) and Lempel-Ziv entropy coding (data compressor/decompressor). The chips can be used independently or together as a transform coding chip set for image compression. The algorithms and chip architectures of the transform codec (S-transform processor) and the entropy codec (data compressor/decompressor) are described.< >

关键词： transform coding Image coding Codecs Application specific integrated circuits Entropy coding

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An efficient (SPST) and its applications on MPEG-4 AVC/H.264 transform coding design

An efficient (SPST) and its applications on MPEG-4 AVC/H.264...

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International Symposium on Low Power Electronics and Design (ISLPED)

作者： Kuan-Hung Chen Kuo-Chuan Chao Jinn-Shyan Wang Yuan-Sun Chu Jiun-ln Guo Department of Electrical Engineering National Chung Cheng University Chiayi Taiwan Department of Computer Science and Information Engineering National Chung Cheng University Chiayi Taiwan

This paper proposes an efficient spurious power suppression technique (SPST) and its applications on an MPEG-4 AVC/H.264 transform coding design. There are three techniques addressed in this paper, which are (1) the SPST, (2) the direct 2-D algorithm, and (3) the interlaced I/O schedule to solve the design challenges induced by both the real-time processing and low-power requirements. The major novelty of this paper is implementing the SPST concept on the transform architecture for H.264, which save 31.9% power consumption at the cost of 20.9% area price. Moreover, the proposed transform design also possesses 60.05% higher hardware efficiency through the TPUA index than the existing designs.

关键词： MPEG 4 Standard Automatic voltage control transform coding Motion pictures Throughput Application software Very large scale integration Codecs Data processing Algorithm design and analysis

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