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2024 International Conference on Image Processing

作者： Nishimura, Hitoshi Kato, Haruhisa Kawamura, Kei KDDI Res Inc Saitama Japan

ISBN: (纸本)9798350349405;9798350349399

Dynamic meshes reasonably represent time-varying 3D objects, but compression is required due to the large amount of data involved. One efficient framework decomposes a dynamic mesh into a base mesh and displacements using decimation and subdivision. The displacements are converted to levels by wavelet transforms and quantization, and they are coded by arithmetic coding. The levels of the current frame are predicted from the reference frame, and only the residuals are coded. However, quantization errors occur two times in the reference frame and the current frame since the coefficients of each frame are quantized before performing inter prediction. In this paper, we propose a method of quantizing the residuals obtained after applying inter prediction in order to reduce the amount of required data. The experimental results show that the proposed method yields improved coding efficiency and that the reconstructed mesh has no quality degradations.

关键词： dynamic mesh displacements arithmetic coding quantization inter prediction

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Data encryption scheme with extended artithmetic coding

Data encryption scheme with extended artithmetic coding

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4th Conference on Mathematics of Image and Data coding, Compression, and Encryption

作者： Ishibashi, H Tanaka, K Shinshu Univ Fac Engn Nagano 3808553 Japan

ISBN: (纸本)0819441899

In this work, we extend arithmetic coding and present a data encryption scheme that achieves data compression and data security at the same time. This scheme is based on a chaotic dynamics, which makes use of the fact that the decoding process of arithmetic coding scheme can be considered as the repetition of Bernoulli shift map. Data encryption is achieved by controlling the piecewise linear maps by a secret key in three kinds of approach: (i) perturbation method, (ii) switching method, and (iii) source extension method. Experimental results show that the obtained arithmetic codes for a message are randomly distributed on the mapping domain [0,1) by using different keys without seriously deteriorating the compression ratio, and the transition of the orbits in the domain [0,1) is similar to the chaotic dynamics.

关键词： arithmetic coding data encryption data compression chaotic dynamical system pieceivise linear map

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Cryptanalysis of a chaos-based cryptosystem with an embedded adaptive arithmetic coder

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Chinese Physics B 2011年第8期20卷 97-105页

作者：王兴元谢旖欣 School of Electronic & Information Engineering Dalian University of Technology

In this paper, we analyse a new chaos-based cryptosystem with an embedded adaptive arithmetic coder, which was proposed by Li Heng-Jian and Zhang J S （Li H J and Zhang J S 2010 Chin. Phys. B 19 050508）. Although this new method has a better compression performance than its original version, it is found that there are some problems with its security and decryption processes. In this paper, it is shown how to obtain a great deal of plain text from the cipher text without prior knowledge of the secret key. After discussing the security and decryption problems of the Li Heng-Jian et al. algorithm, we propose an improved chaos-based cryptosystem with an embedded adaptive arithmetic coder that is more secure.

关键词： chaos cryptography compression arithmetic coding

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On Entropy-Constrained Vector Quantization using Gaussian Mixture Models

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IEEE TRANSACTIONS ON COMMUNICATIONS 2008年第12期56卷 2094-2104页

作者： Zhao, David Y. Samuelsson, Jonas Nilsson, Mattias Royal Inst Technol Sch Elect Engn Stockholm Sweden Dolby Labs Stockholm Sweden

A flexible and low-complexity entropy-constrained vector quantizer (ECVQ) scheme based on Gaussian mixture models (GMMs), lattice quantization, and arithmetic coding is presented. The source is assumed to have a probability density function of a GMM. An input vector is first classified to one of the mixture components, and the Karhunen-Loeve transform of the selected mixture component is applied to the vector, followed by quantization using a lattice structured codebook. Finally, the scalar elements of the quantized vector are entropy coded sequentially using a specially designed arithmetic coder. The computational complexity of the proposed scheme is low, and independent of the coding rate in both the encoder and the decoder. Therefore, the proposed scheme serves as a lower complexity alternative to the GMM based ECVQ proposed by Gardner, Subramaniam and Rao [1]. The performance of the proposed scheme is analyzed under a high-rate assumption, and quantified for a given GMM. The practical performance of the scheme was evaluated through simulations on both synthetic and speech line spectral frequency (LSF) vectors. For LSF quantization, the proposed scheme has a comparable performance to [1] at rates relevant for speech coding (20-28 bits per vector) with lower computational complexity.

关键词： Entropy constrained vector quantization VQ lattice Gaussian mixture model GMM arithmetic coding

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DATA-COMPRESSION OF ECG BASED ON THE EDIT DISTANCE ALGORITHMS

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IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS 1993年第12期E76D卷 1443-1453页

作者： MORITA, H KOBAYASHI, K Electro-Communications Tokyo Japan

A method for the compression of ECG data is presented. The method is based on the edit distance algorithm developed in the file comparison problems. The edit distance between two sequences of symbols is defined as the number of edit operations required to transform a sequence of symbols into the other. We adopt the edit distance algorithm to obtain a list of edit operations, called edit script, which transforms a reference pulse into a pulse selected from ECG data. If the decoder knows the same reference, it can reproduce the original pulse, only from the edit script. The amount of the edit script is expected to be smaller than that of the original pulse when the two pulses look alike and thereby we can reduce the amount of space to store the data. Applying the proposed scheme to the raw data of ECG, we have achieved a high compression about 14 : 1 without losing the significant features of signals.

关键词： ECG DATA COMPRESSION arithmetic coding EDIT DISTANCE DP MATCHING

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Embedding adaptive arithmetic coder in chaos-based cryptography

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Chinese Physics B 2010年第5期19卷 121-129页

作者：李恒建张家树 Sichuan Province Key Lab of Signal & Information Processing Southwest Jiaotong University

In this study an adaptive arithmetic coder is embedded in the Baptista-type chaotic cryptosystem for implementing secure data compression. To build the multiple lookup tables of secure data compression, the phase space of chaos map with a uniform distribution in the search mode is divided non-uniformly according to the dynamic probability estimation of plaintext symbols. As a result, more probable symbols are selected according to the local statistical characters of plaintext and the required number of iterations is small since the more probable symbols have a higher chance to be visited by the chaotic search trajectory. By exploiting non-uniformity in the probabilities under which a number of iteration to be coded takes on its possible values, the compression capability is achieved by adaptive arithmetic code. Therefore, the system offers both compression and security. Compared with original arithmetic coding, simulation results on Calgary Corpus files show that the proposed scheme suffers from a reduction in compression performance less than 12% and is not susceptible to previously carried out attacks on arithmetic coding algorithms.

关键词： chaos cryptography compression arithmetic coding

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An embedded wavelet packet image coding algorithm

An embedded wavelet packet image coding algorithm

引用

IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Hou, XS Liu, GZ Li, HL Li, YL Xi An Jiao Tong Univ Sch Elect & Informat Engn Xian 710049 Peoples R China

ISBN: (纸本)0780374029

In this paper, we presented a novel wavelet packet image coding approach which provides the functionality of fine granular bitstream scalability. The proposed progressive wavelet packet image coding scheme consists of three parts, wavelet packet decomposition, a quadtree sorting procedure for classifying wavelet coefficients and universal trellis-coded quantization for quantizing the sorted coefficients. The image coding results, calculated in PSNR and images reconstructed by the decoding algorithm, are either comparable to or surpass previous results, due to the flexible representation ability of wavelet packet, the effective quadtree classifier and the improved granular fidelity of the UTCQ over scalar quantization.

关键词： image coding quantisation (signal) wavelet transforms transform coding quadtrees sorting image reconstruction decoding arithmetic codes embedded wavelet packet image coding fine granular bitstream scalability quadtree sorting procedure universal trellis-coded quantization PSNR image reconstruction scalar quantization arithmetic coding

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Power-Saving 8K Real-Time AV1 arithmetic Encoder Architecture

IEEE DESIGN & TEST

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IEEE DESIGN & TEST 2022年第6期39卷 128-137页

作者： Bitencourt, Tulio Pereira Livi Ramos, Fabio Luis Bampi, Sergio Univ Fed Rio Grande do Sul PGMICRO BR-91501970 Porto Alegre RS Brazil EnSil Brasil Ltd BR-90619900 Porto Alegre RS Brazil Fed Univ Pampa BR-96413172 Bage Brazil

This article presents high-throughput and low-power hardware architecture versions for the arithmetic encoding block used in AV1 video codec.

关键词： Symbols Encoding arithmetic Streaming media Pipelines Computer architecture Table lookup Video codecs Throughput AV1 video coding arithmetic coding hardware architecture

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A large-alphabet-oriented scheme for Chinese and English text compression

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SOFTWARE-PRACTICE & EXPERIENCE 2005年第11期35卷 1027-1039页

作者： Gu, HY Natl Taiwan Univ Sci & Technol Dept Comp Sci & Informat Engn Taipei Taiwan

In this paper, a large-alphabet-oriented scheme is proposed for both Chinese and English text compression. Our scheme parses Chinese text with the alphabet defined by Big-5 code, and parses English text with some rules designed here. Thus, the alphabet used for English is not a word alphabet. After a token is parsed out from the input text, zero-, first-, and second-order Markov models are used to estimate the occurrence probabilities of this token. Then, the probabilities estimated are blended and accumulated in order to perform arithmetic coding. To implement arithmetic coding under a large alphabet and probability-blending condition, a way to partition count-value range is studied. Our scheme has been programmed and can be executed as a software package. Then, typical Chinese and English text files are compressed to study the influences of alphabet size and prediction order. On average, our compression scheme can reduce a text file's size to 33.9% for Chinese and to 23.3% for English text. These rates are comparable with or better than those obtained by popular data compression packages. Copyright (C) 2005 John Wiley & Sons, Ltd.

关键词： text compression large alphabet Markov modeling arithmetic coding

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Interval algorithm for random number generation

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IEEE TRANSACTIONS ON INFORMATION THEORY 1997年第2期43卷 599-611页

作者： Han, TS Hoshi, M Sch. of Inf. Syst. Univ. of Electro-Commun. Tokyo Japan Graduate School of Information Systems University of Electro-Communications Chofu Tokyo Japan

The problem of generating a random number with an arbitrary probability distribution by using a general biased M-coin is studied, An efficient and very simple algorithm based on the successive refinement of partitions of the unit interval [0, 1), which we call the interval algorithm, is proposed, A fairly tight evaluation on the efficiency is given, Generalizations of the interval algorithm to the following cases are investigated: 1) output sequence is independent and identically distributed (i.i.d.);2) output sequence is Markov;3) input sequence is Markov;4) input sequence and output sequence are both subject to arbitrary stochastic processes.

关键词： random number generation interval algorithm partitions entropy biased coin arithmetic coding

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