检索结果-内蒙古大学图书馆

A learned pixel-by-pixel lossless image compression method with 59K parameters and parallel decoding

MULTIMEDIA TOOLS AND APPLICATIONS 2023年第8期83卷 22975-22993页

作者： Guemues, Sinem Kamisli, Fatih Middle East Tech Univ Elect & Elect Engn TR-06800 Ankara Turkiye

This paper considers lossless image compression and presents a learned compression system that can achieve state-of-the-art lossless compression performance but uses only 59K parameters, which is one or two order of magnitudes less than other learned systems proposed recently in the literature. The explored system is based on a learned pixel-by-pixel lossless image compression method, where each pixel's probability distribution parameters are obtained by processing the pixel's causal neighborhood (i.e. previously encoded/decoded pixels) with a simple neural network comprising 59K parameters. This causality causes the decoder to operate sequentially, i.e. the neural network has to be evaluated for each pixel sequentially, which increases decoding time significantly with common GPU software and hardware. To reduce the decoding time, parallel decoding algorithms are proposed and implemented. The obtained lossless image compression system is compared to traditional and learned systems in the literature in terms of compression performance, encoding-decoding times and computational complexity.

关键词： Image compression Artificial neural networks entropy coding Gaussian mixture model

来源：评论

学校读者我要写书评

暂无评论

An Improved Method to CABAC in the H.264/AVC Video Compression Standard

引用

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2009年第12期E92A卷 3355-3360页

作者： Ha, LeThanh Park, Chun-Su Jung, Seung-Won Ko, Sung-Jea Korea Univ Dept Elect Engn Seoul 136701 South Korea

Context-based Adaptive Binary Arithmetic coding (CABAC) is adopted as an entropy coding tool for main profile of the video coding standard H.264/AVC, CABAC achieves higher degree of redundancy reduction by estimating the conditional probability of each binary symbol which is the input to the arithmetic coder. This paper presents an entropy coding method based on CABAC. In the proposed method, the binary symbol is coded using more precisely estimated conditional probability, thereby leading to performance improvement. We apply our method to the standard and evaluate its performance for different video sources and various quantization parameters (QP). Experiment results show that our method outperforms the original CABAC in term of coding efficiency, and the average bit-rate savings are up to 1.2%.

关键词： H264/AVC entropy coding arithmetic codes CABAC linear regression

来源：评论

学校读者我要写书评

暂无评论

A low-complexity method for fixed-rate entropy-constrained vector quantization

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2006年第6期54卷 1030-1037页

作者： Nikneshan, S Khandani, AK Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

This paper describes a new approach to fixed-rate entropy-constrained vector quantization (FEVQ) for stationary memoryless sources where the structure of codewords are derived from a variable-length scalar quantizer. We formulate the quantization search operation as a zero-one integer-optimization problem, and show that the resulting integer program can be closely approximated by solving a simple linear program. The result is a Lagrange formulation which adjoins the constraint on the entropy (codeword length) to the distortion. Unlike the previously known methods with a fixed Lagrange multiplier, we use an iterative algorithm to optimize the underlying objective function, while updating the Lagrange multiplier until the constraint on the overall rate is satisfied. The key feature of the new method is the substantial reduction in the number of iterations in comparison with previous related methods. In order to achieve some packing gain, we combine the process of trellis-coded quantization with that of FEVQ. This results in an iterative application of the Viterbi algorithm on the underlying trellis for selecting the Lagrange multiplier. Numerical results are presented which demonstrate substantial improvement in comparison with the alternative methods reported in the literature.

关键词： entropy coding linear programming source coding trellis-coded quantization vector quantization

来源：评论

学校读者我要写书评

暂无评论

An efficient approach to lattice-based fixed-rate entropy-coded vector quantization

引用

EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS 2003年第2期14卷 141-147页

作者： Nikneshan, S Khandani, AK Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

In the absence of channel noise, variable-length quantizers perform better than fixed-rate Lloyd-Max quantizers for any source with a non-uniform density function. However, channel errors can lead to a loss of synchronization resulting in a propagation of error. To avoid having variable rate, one can use a vector quantizer selected as a sub-set of high probability points in the Cartesian product of a set of scalar quantizers and represent its elements with binary code-words of the same length (quantizer shaping). We choose these elements from a lattice, resulting in a higher quantization gain in comparison to simply using the Cartesian product of a set of scalar quantizers. We introduce a class of lattices which have a low encoding complexity, and at the same time result in a noticeable quantization gain. We combine the procedure of lattice encoding with that of quantizer shaping using hierarchical dynamic programming. In addition, by devising appropriate partitioning and merging rules, we obtain sub-optimum schemes of low complexity and small performance degradation. The proposed methods show a substantial improvement in performance and/or a reduction in the complexity with respect to the best known results. Copyright (C) 2003 AEI.

关键词： Elements crystal lattices quantizer degradation of performance entropy coding Cartesian product Vector quantization encoding complexity

来源：评论

学校读者我要写书评

暂无评论

Lossless image compression by using gradient adjusted prediction and Burrows-Wheeler transformation

引用

IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 1999年第2期45卷 380-386页

作者： Ng, KS Cheng, LM City Univ Hong Kong Dept Elect Engn 83 Tat Chee Ave Kowloon Peoples R China

In generally text compression techniques cannot be used directly in image compression because the model of text and image are different. Recently, a new class of text compression, namely, block-sorting algorithm which involves Burrows and Wheeler transformation (BWT) gives excellent results in text compression. However, if we apply it directly into image compression, the result is poor. Surprisingly, good results can be obtained if we employ a prediction model such as the one defined in JPEG standard before the BWT algorithm. Thus, the predictive model plays critical role - in the compression process. To further improve the compression efficiency, we use Gradient Adjusted Prediction (GAP). Experimental results show that the proposed method is better than lossless JPEG and some LZ-based compression methods.

关键词： Image coding Transform coding Sorting Predictive models Compression algorithms Data compression ISO standards IEC standards entropy coding Performance loss

来源：评论

学校读者我要写书评

暂无评论

An Audio Compression Method Based on Wavelets Subband coding

引用

IEEE LATIN AMERICA TRANSACTIONS 2011年第5期9卷 610-621页

作者： Kemper, G. Iano, Y. Univ Estadual Campinas UNICAMP Sao Paulo Brazil

This paper presents an audio compression method based on wavelets sub-band quantization and coding, and proposes a coder based on that method. The proposed coder uses the wavelets packets transform in order to obtain the critical bands of the human auditory system. Some results of the MPEG-layer 2 psychoacoustic model are used in the wavelets coefficients coding. The MPEG results are transformed to the wavelet domain in order to determinate the quantizer type and the quantization levels number for each wavelet sub-band. The transform method of these results is also proposed. The coder uses scalar and vector quantization methods according with the sensibility of the human auditory system for each wavelet sub-band. The entropy coding is also used in order to improve the performance of the proposed coder. The results of the subjective evaluation demonstrate that the proposed coder achieve transparent coding of the monophonic CD signals at bit rates of 80-96 Kbit/seg.

关键词： audio coding wavelet transform MPEG quantization entropy coding subjective evaluation

来源：评论

学校读者我要写书评

暂无评论

Context modeling based on context quantization with application in wavelet image coding

引用

IEEE TRANSACTIONS ON IMAGE PROCESSING 2004年第1期13卷 26-32页

作者： Chen, JH Yunnan Univ Dept Elect Engn Kunming 650091 Peoples R China

Context modeling is widely used in image coding to improve the compression performance. However, with no special treatment, the expected compression gain will be cancelled by the model cost introduced by high order context models. Context quantization is an efficient method to deal with this problem. In this paper, we analyze the general context quantization problem in detail and show that context quantization is similar to a common vector quantization problem. If a suitable distortion measure is defined, the optimal context quantizer can be designed by a Lloyd style iterative algorithm. This context quantization strategy is applied to an embedded wavelet coding scheme in which the significance map symbols and sign symbols are directly coded by arithmetic coding with context models designed by the proposed quantization algorithm. Good coding performance is achieved.

关键词： context modeling entropy coding image coding quantization wavelet

来源：评论

学校读者我要写书评

暂无评论

Using Four Hypothesis Probability Estimators for CABAC in Versatile Video coding

引用

ACM TRANSACTIONS ON MULTIMEDIA COMPUTING COMMUNICATIONS AND APPLICATIONS 2023年第1期19卷 1-17页

作者： Chan, Ka-Hou Im, Sio-Kei Macao Polytech Univ Fac Appl Sci Macau 999078 Peoples R China Macao Polytech Univ Macau 999078 Peoples R China

This article introduces the key technologies involved in four hypothetical probability estimators for Context-based Adaptive Binary Arithmetic coding (CABAC). The focus is on the selected adaptation rate performed in these estimators, which are selected based on coding efficiency and memory considerations, and also the relationship with the current size of the coding block. The proposed scheme can linearly realize the quantitative representation of probabilistic prediction and describes the scalability potential for higher accuracy. Besides a description of the design concept, this work also discusses motivation and implementation aspects, which are based on simple operations such as bitwise operations and single subsampling for subinterval updates. The experimental results verify the effectiveness of the proposed CABAC method specified in Versatile Video coding (VVC).

关键词： VVC CABAC entropy coding probability estimator adaptation rate video compression

来源：评论

学校读者我要写书评

暂无评论

Lossless compression of chemical fingerprints using integer entropy codes improves storage and retrieval

引用

JOURNAL OF CHEMICAL INFORMATION AND MODELING 2007年第6期47卷 2098-2109页

作者： Baldi, Pierre Benz, Ryan W. Hirschberg, Daniel S. Swamidass, S. Joshua Univ Calif Irvine Sch Informat & Comp Sci Inst Genom & Bioinformat Irvine CA 92697 USA

Many modem chemoinformatics systems for small molecules rely on large fingerprint vector representations, where the components of the vector record the presence or number of occurrences in the molecular graphs of particular combinatorial features, such as labeled paths or labeled trees. These large fingerprint vectors are often compressed to much shorter fingerprint vectors using a lossy compression scheme based on a simple modulo procedure. Here, we combine statistical models of fingerprints with integer entropy codes, such as Golomb and Elias codes, to encode the indices or the run lengths of the fingerprints. After reordering the fingerprint components by decreasing frequency order, the indices are monotone-increasing and the run lengths are quasi-monotone-increasing, and both exhibit power-law distribution trends. We take advantage of these statistical properties to derive new efficient, lossless, compression algorithms for monotone integer sequences: monotone value (MOV) coding and monotone length (MOL) coding. In contrast to lossy systems that use 1024 or more bits of storage per molecule, we can achieve lossless compression of long chemical fingerprints based on circular substructures in slightly over 300 bits per molecule, close to the Shannon entropy limit, using a MOL Elias Gamma code for run lengths. The improvement in storage comes at a modest computational cost. Furthermore, because the compression is lossless, uncompressed similarity (e.g., Tanimoto) between molecules can be computed exactly from their compressed representations, leading to significant improvements in retrival performance, as shown on six benchmark data sets of druglike molecules.

关键词： Fingerprints Integer Storage storage and retrieval entropy coding lossy compression lossless compression statistical models (nuclear)

来源：评论

学校读者我要写书评

暂无评论

Improved Efficiency on Adaptive Arithmetic coding for Data Compression Using Range-Adjusting Scheme, Increasingly Adjusting Step, and Mutual-Learning Scheme

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2018年第12期28卷 3412-3423页

作者： Ding, Jian-Jiun Wang, I-Hsiang Chen, Hung-Yi Natl Taiwan Univ Grad Inst Commun Engn Taipei 10617 Taiwan

Context-based adaptive arithmetic coding (CAAC) has high coding efficiency and is adopted by the majority of advanced compression algorithms. In this paper, five new techniques are proposed to further improve the performance of CAAC. They make the frequency table (the table used to estimate the probability distribution of data according to the past input) of CAAC converge to the true probability distribution rapidly and hence improve the coding efficiency. Instead of varying only one entry of the frequency table, the proposed range-adjusting scheme adjusts the entries near to the current input value together. With the proposed mutual-learning scheme, the frequency tables of the contexts highly correlated to the current context are also adjusted. The proposed increasingly adjusting step scheme applies a greater adjusting step for recent data. The proposed adaptive initialization scheme uses a proper model to initialize the frequency table. Moreover, a local frequency table is generated according to local information. We perform several simulations on edge-directed prediction-based lossless image compression, coefficient encoding in JPEG, bit plane coding in JPEG 2000, and motion vector residue coding in video compression. All simulations confirm that the proposed techniques can reduce the bit rate and are beneficial for data compression.

关键词： Data compression adaptive arithmetic coding context-based adaptive arithmetic coding entropy coding lossless image compression by edge-directed prediction

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：