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COMPARATIVE PERFORMANCE OF SVD AND adaptive COSINE TRANSFORM IN coding IMAGES

IEEE TRANSACTIONS ON COMMUNICATIONS 1979年第8期27卷 1230-1234页

作者： GARGUIR, N Centre National d'Etudes Spatiales Toulouse France

An adaptive coding for singular value decomposition (SVD) samples is described in order to reduce the amount of transmitted data for monochrome images. This method is compared to the discrete cosine transform in terms of mean square error. Low bit rates, as 0.8 bits/pixel, are attempted with a good visual quality and low RMS error (0.087%). The visual and mathematical results of the transmission errors are shown and given.

关键词： Image coding Singular value decomposition Bit rate Discrete transforms Computer errors Entropy adaptive coding Discrete cosine transforms Mean square error methods Satellites

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A Video coding Scheme with adaptive Intra-frame Selection

A Video Coding Scheme with Adaptive Intra-frame Selection

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International Conference on Computer Sciences and Applications (CSA)

作者： Guo, Tianhao Guo, Dabo Xidian Univ State Key Lab Integrated Serv Networks Xian 710071 Peoples R China Shanxi Univ Coll Phys & Elect Engn Taiyuan 030006 Peoples R China

ISBN: (纸本)9780769551258

Intra-frame coding costs much more bits than inter-frame coding in a video encoder. The Assignment of the intra-frames is independent of video contents in current CODEC. This work proposes an adaptive Delaunay triangular mesh (DTM) based motion estimation/motion compensation (ME/MC) and DCT hybrid coding scheme with an ability to perceive the change of the content of any videos and assign the intra-frame in the moment with an abrupt change in contents of picture, e.g. an occlude object (objects) entering picture. This mechanism improves coding efficiencies. Scene-adaptive DTM generation algorithm is firstly present. Moreover, two-stage successive nodal tracking, which guarantees correct correspondence searching and prohibits the degeneration of the meshes, is then proposed. Furthermore, a steepest descent algorithm is derived in detail in effort to speed up the optimization process. Finally, a framework of the coding scheme and a brief description of the implementation methods are present. The experiment results demonstrate the adaptive intra frame refresh and other benefits in compression efficiency.

关键词： video coding Delaunay triangulation adaptive coding

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adaptive Reed-Solomon coding in Eigen-MIMO with Non-adaptive Modulation

Adaptive Reed-Solomon Coding in Eigen-MIMO with Non-Adaptive...

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IEEE 74th Vehicular Technology Conference (VTC)

作者： Banani, S. Alireza Vaughan, Rodney G. Simon Fraser Univ Sch Engn Sci Burnaby BC V5A 1S6 Canada

ISBN: (纸本)9781424483273

An adaptive coding scheme for spectral efficiency improvement in eigen-MIMO is presented. It uses Reed-Solomon (RS) codes with non-adaptive QAM. Non-adaptive modulation is of interest since it reduces the high complexity - in both the electronics and the protocol - required for deploying the more commonly treated adaptive modulation. RS codes have practical advantages in terms of their algorithmic simplicity, memory requirements and decoder complexity. Unlike many codes, an analytical solution for the error probability is available for RS coding. This facilitates finding the jointly optimal code rate(s) and power allocation on the eigenchannels, with the criterion of maximum instantaneous practicable capacity (data throughput). The adaptation is applied to two different architectures of the encoders/decoders (CODECs) for eigen-MIMO, and their performances are compared with the uncoded case. The outer coding architecture refers to a single CODEC working on the overall serial data, and inner coding refers to separate CODECs for different eigenchannels. The adaptive RS system with optimum power allocation reveals new capacity behavior which is different to that of water-filling. For the moderate values of SNR (6-20 dB) typical of wireless systems, the improvement in the capacity over the no-coding case is greater for the inner coding architecture.

关键词： adaptive coding MIMO water filling eigenchannel ergodic capacity practicable capacity Reed-Solomon coding

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Compression of medical images through adaptive block-size DCT coding

Compression of medical images through adaptive block-size DC...

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Conference on Image Display

作者： Chong, MN Ang, EL Tan, CS Loo, CZ NANYANG TECHNOL UNIV SCH APPL SCISINGAPORE 639798SINGAPORE

ISBN: (纸本)0819420824

Compression of medical images to reduce their storage and transmission bandwidth requirements is of great interest in the implementation of systems such as the picture archiving and communication system (PACS). Direct application of discrete cosine transform (DCT) coding to medical images such as CT or MRI images is not effective as the characteristics of such medical images are not exploited. Firstly, the noisy background in medical images exhibits largely uncorrelated data which is difficult to compress using transform coding. Secondly, the overhead in representing the background information using fixed block-size transform coding is inefficient. A novel adaptive coding algorithm is proposed to yield high compression rate for medical images. The proposed algorithm is a two-stage process: the first stage (pre-processing stage) attempts to remove the background noise and identifies the border of the medical data by using a visual mask; the second stage (encoding stage) uses an adaptive block-size DCT coding algorithm to compress the image data. The proposed coding algorithm is evaluated and compared with the JPEG baseline algorithm where results on the compression ratio and peak signal-to-noise ratio (PSNR) are presented. The results show that the proposed coding algorithm achieves a higher compression rate than the JPEG baseline algorithm. In addition, the PSNR values of the new coder is marginally higher than the results obtained with the JPEG coder.

关键词： visual mask thresholding Discrete Cosine Transform (DCT) adaptive coding variable block-size quad-tree

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adaptive wavelet image block coding

Adaptive wavelet image block coding

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Wavelet Applications III Conference

作者： Uhl, A SALZBURG UNIV RES INST SOFTWARETECHNOLA-5020 SALZBURGAUSTRIA

ISBN: (纸本)081942143X

In this paper a new approach for adaptive wavelet image coding is introduced. Based on an adaptive quadtree image-block partition (similar to fractal coding) the different image blocks may be compressed independently in an adaptive manner. In order to adapt to local image statistics and features we present several possibilities of how to optimize the transform part of a wavelet image block-coder. Additionally we present a parallel algorithm suitable for MIMD architectures for efficient implementation of the proposed method. Finally experimental results concerning coding efficiency and execution time on a cluster of workstations are described.

关键词： image compression wavelets parallel algorithms adaptive coding

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4D-MDCT based adaptive prediction and compensation color video coding

4D-MDCT based adaptive prediction and compensation color vid...

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7th International Conference on Signal Processing

作者： Du, XW Chen, HX Zhao, ZJ Jilin Univ Inst Commun ENgn Changchun 130025 Peoples R China

ISBN: (纸本)7121002159

In order to increase the compression ratio of color video sequence, a new adaptive coding method based on four-dimensional matrix theories is proposed in this paper. A four-dimensional matrix model is adopted to describe the color video sequence. 4D-MDCT(four-dimensional matrix DCT) is used to decrease the correlation of intra frames and inter frames. Then, the coefficients are quantized by quantization matrix. To get rid of the correlation between the coefficients farther, prediction and compensation are applied to the quantized coefficients. At the same time, the original quantized coefficients of the submatrix are coded too. Select the, coding method, which consumes fewer bits, as the final method for each submatrix adaptively. Experimental results show that high compression ratio can be achieved and the high PSNR preserved.

关键词： color video 4D-MDCT prediction compensation adaptive coding

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Towards MPEG-4 part 10 system on chip: A VLSI prototype for Context-based adaptive Variable Length coding (CAVLC)

Towards MPEG-4 part 10 system on chip: A VLSI prototype for ...

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IEEE Workshop on Signal Processing Systems Design and Implementation

作者： Amer, I Badawy, W Jullien, G ATIPS Calgary AB T2N 1N4 Canada

ISBN: (纸本)0780385047

This paper presents a VLSI prototype for Context-based adaptive Variable Length coding (CAVLC). This scheme is a part of the lossless compression process in the MPEG-4 Part 10 standard. It is applied to the quantized transform coefficients of the luminance component during the entropy coding process. In combination with previous transformations and quantizations, it can result in significantly increased compression ratio. The developed architecture is prototyped and simulated using ModelSim 5.40. It is synthesized using Synplify Pro 7.1(R). The results show that the architecture satisfies the real-time constraints required by different digital video applications.

关键词： data compression video coding system-on-chip VLSI entropy codes variable length codes adaptive codes quantisation (signal) hardware description languages hardware-software codesign MPEG-4 Part 10 standard system on chip VLSI prototype context-based adaptive variable length coding lossless compression process quantized transform coefficients luminance component entropy coding quantization ModelSim 5.4 Synplify Pro 7.1 real-time constraints digital video VHDL language CAVLC system-on-chip Entropy coding variable length codes adaptive coding Digital video Hardware/software co-design Quantization Data compression Video coding Time constraints

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adaptive COMPRESSED SENSING - A NEW CLASS OF SELF-ORGANIZING coding MODELS FOR NEUROSCIENCE

ADAPTIVE COMPRESSED SENSING - A NEW CLASS OF SELF-ORGANIZING...

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2010 IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Coulter, William K. Hillar, Christopher J. Isley, Guy Sommer, Friedrich T. Univ Calif Berkeley 156 Stanley HallMC 3220 Berkeley CA 94720 USA Math Sci Res Inst Berkeley CA 94120 USA

ISBN: (纸本)9781424442966

Sparse coding networks, which utilize unsupervised learning to maximize coding efficiency, have successfully reproduced response properties found in primary visual cortex [1]. However, conventional sparse coding models require that the coding circuit can fully sample the sensory data in a one-to-one fashion, a requirement not supported by experimental data from the thalamo-cortical projection. To relieve these strict wiring requirements, we propose a sparse coding network constructed by introducing synaptic learning in the framework of compressed sensing. We demonstrate a new model that evolves biologically realistic, spatially smooth receptive fields despite the fact that the feedforward connectivity subsamples the input and thus the learning must rely on an impoverished and distorted account of the original visual data. Further, we demonstrate that the model could form a general scheme of cortical communication: it can form meaningful representations in a secondary sensory area, which receives input from the primary sensory area through a "compressing" cortico-cortical projection. Finally, we prove that our model belongs to a new class of sparse coding algorithms in which recurrent connections are essential in forming the spatial receptive fields.

关键词： adaptive coding biological system modeling random codes image coding nonlinear circuits

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Learned Hierarchical B-frame coding with adaptive Feature Modulation for YUV 4:2:0 Content

Learned Hierarchical B-frame Coding with Adaptive Feature Mo...

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56th IEEE International Symposium on Circuits and Systems (ISCAS)

作者： Chen, Mu-Jung Xie, Hong-Sheng Chien, Cheng Peng, Wen-Hsiao Hang, Hsueh-Ming Natl Yang Ming Chiao Tung Univ Comp Sci Dept Hsinchu Taiwan Natl Yang Ming Chiao Tung Univ Elect Engn Dept Hsinchu Taiwan

ISBN: (纸本)9781665451093

This paper introduces a learned hierarchical B-frame coding scheme in response to the Grand Challenge on Neural Network-based Video coding at ISCAS 2023. We address specifically three issues, including (1) B-frame coding, (2) YUV 4:2:0 coding, and (3) content-adaptive variable-rate coding with only one single model. Most learned video codecs operate internally in the RGB domain for P-frame coding. Bframe coding for YUV 4:2:0 content is largely under-explored. In addition, while there have been prior works on variable-rate coding with conditional convolution, most of them fail to consider the content information. We build our scheme on conditional augmented normalized flows (CANF). It features conditional motion and inter-frame codecs for efficient B-frame coding. To cope with YUV 4:2:0 content, two conditional inter-frame codecs are used to process the Y and UV components separately, with the coding of the UV components conditioned additionally on the Y component. Moreover, we introduce adaptive feature modulation in every convolutional layer, taking into account both the content information and the coding levels of B-frames to achieve content-adaptive variable-rate coding. Experimental results show that our model outperforms x265 and the winner of last year's challenge on commonly used datasets in terms of PSNR-YUV.

关键词： video compression YUV 4:2:0 format variable rate adaptive coding

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Fast Practical adaptive Encoding on Large Alphabets

Fast Practical Adaptive Encoding on Large Alphabets

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Data Compression Conference (DCC)

作者： Igor Zavadskyi Taras Shevchenko National University of Kyiv Kyiv Ukraine

ISBN: (数字)9798331534714

ISBN: (纸本)9798331534721

We present two adaptive coding methods that perform especially well on large alphabets like those used in word-level text compression. The first is based on re-indexing a universal codeword set. The more evolved second method assumes that the underlying codeword set can be optimized and re-generated efficiently. Experiments show that this method, using the Binary Mixed-digit codes as an underlying solution, produces about 1% bigger compressed files than the classical Vitter's algorithm adapted to large alphabets, being more than an order of magnitude faster in encoding and decoding.

关键词： Computer languages Costs Codes Symbols Encoding Decoding adaptive coding

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