检索结果-内蒙古大学图书馆

Secure Real-Time Chaotic Partial Encryption of entropy-Coded Multimedia Information for Mobile Devices: Smartphones

IEEE ACCESS 2022年 10卷 15876-15890页

作者： Hasimoto-Beltran, Rogelio Calderon-Calderon, Marcos D. Olavarria-Jaramillo, Victor H. Ctr Res Math CIMAT AC Guanajuato 36023 Gto Mexico

Smartphones penetration-rate continues expanding, from 44% in 2017 up to 59% expected increase in 2022 as reported by Strategy Analytics. At present, smartphones dominate the global mobile traffic, which in turn is dominated by video communications. For mobile systems with limited power capabilities, the processing of real-time multimedia information with affixed security represents a real challenge. In this work, we propose a high-performance encryption scheme capable of running on low-power smartphones without holding back video coding operation. We are aimed at destroying the meaning of the entropy coded bitstream by inserting random bit errors to induce error propagation and impede natural self-resynchronization process. The scheme consists of three main process: 1) A new integer chaos-based Coupled-Map Lattice-CML for creating secure pseudo-random trajectories;2) Random bit flipping of the bitstream based on a Dynamic Reference Point (DRP) not exposed to attackers;and 3) Random selection of CML byte-trajectories for both DRP and bit flipping processes for increased security. Implementation of the scheme on smartphones with different CPU-power capabilities shows excellent performance to handle high-bandwidth real-time video smoothly (one-to-one and group calls). The scheme provides high scalable security with encrypted data volume fluctuating between 0.7%-3% of the total compressed data (video and still images).

关键词： Encryption Cryptography Streaming media Smart phones Image coding entropy Transform coding Chaotic systems coupled-map lattice entropy coding partial encryption

来源：评论

学校读者我要写书评

暂无评论

The JPEG 2000 still image compression standard

引用

IEEE SIGNAL PROCESSING MAGAZINE 2001年第5期18卷 36-58页

作者： Skodras, A Christopoulos, C Ebrahimi, T Univ Patras Elect Lab GR-26110 Patras Greece Comp Technol Inst GR-26110 Patras Greece Ericsson Res Ericssons Medilab Stockholm Sweden

One of the aims of the standardization committee has been thedevelopment of Part I, which could be used on a royalty- and fee-freebasis. This is important for the standard to become widely accepted. Thestandardization process, which is coordinated by the JTCI/SC29/WG1 ofthe ISO/IEC has already produced the international standard (IS) forPart I. In this article the structure of Part I of the JPFG 2000standard is presented and performance comparisons with establishedstandards are reported. This article is intended to serve as a tutorialfor the JPEG 2000 standard. The main application areas and theirrequirements are given. The architecture of the standard follows withthe description of the tiling, multicomponent transformations, wavelettransforms, quantization and entropy coding. Some of the mostsignificant features of the standard are presented, such asregion-of-interest coding, scalability, visual weighting, errorresilience and file format aspects. Finally, some comparative resultsare reported and the future parts of the standard are discussed

关键词： ISO standards code standards data compression entropy codes image coding quantisation (signal) reviews standardisation telecommunication standards transform coding wavelet transforms ISO/IEC JPEG 2000 still image compression standard Part I standard entr code standards ISO standard image coding Data compression entropy coding transform coding Standardization wavelet transforms

来源：评论

学校读者我要写书评

暂无评论

An Efficient DCT-Based Image Compression System Based on Laplacian Transparent Composite Model

引用

IEEE TRANSACTIONS ON IMAGE PROCESSING 2015年第3期24卷 886-900页

作者： Sun, Chang Yang, En-Hui Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

Recently, a new probability model dubbed the Laplacian transparent composite model (LPTCM) was developed for DCT coefficients, which could identify outlier coefficients in addition to providing superior modeling accuracy. In this paper, we aim at exploring its applications to image compression. To this end, we propose an efficient nonpredictive image compression system, where quantization (including both hard-decision quantization (HDQ) and soft-decision quantization (SDQ)) and entropy coding are completely redesigned based on the LPTCM. When tested over standard test images, the proposed system achieves overall coding results that are among the best and similar to those of H.264 or HEVC intra (predictive) coding, in terms of rate versus visual quality. On the other hand, in terms of rate versus objective quality, it significantly outperforms baseline JPEG by more than 4.3 dB in PSNR on average, with a moderate increase on complexity, and ECEB, the state-of-the-art nonpredictive image coding, by 0.75 dB when SDQ is OFF (i.e., HDQ case), with the same level of computational complexity, and by 1 dB when SDQ is ON, at the cost of slight increase in complexity. In comparison with H.264 intracoding, our system provides an overall 0.4-dB gain or so, with dramatically reduced computational complexity;in comparison with HEVC intracoding, it offers comparable coding performance in the high-rate region or for complicated images, but with only less than 5% of the HEVC intracoding complexity. In addition, our proposed system also offers multiresolution capability, which, together with its comparatively high coding efficiency and low complexity, makes it a good alternative for real-time image processing applications.

关键词： Image coding transparent composite model (TCM) outlier quantization entropy coding

来源：评论

学校读者我要写书评

暂无评论

VERY-LOW BIT-RATE IMAGE-coding ON ADAPTIVE MULTIGRIDS

引用

SIGNAL PROCESSING-IMAGE COMMUNICATION 1995年第4-6期7卷 313-331页

作者： MACQ, B QUELUZ, MP SIMON, B UCL Telecommunications and Remote Sensing Laboratory 2 place du Levant B 1348 Louvain-la-Neuve Belgium

We propose a new approach for very low bit-rate sequence coding (below 64 kbit/s) in which spatial information and temporal changes are encoded using similar tools. In this spatio-temporal integrated approach adaptive multigrids are used for both predicted images (the inter-images) and for the intra-images. The inter-images are mainly encoded by a reliable motion field analyzed and transcribed on an adaptive sampling grid (with variable sampling mesh). The intra-images are encoded using tree segmentation leading to a similar transcription. Universal entropy coding and image reconstruction based on overlapping waveforms are used for both intra-images and inter-images. This coding system is well suited for the cases where regular intra-image refreshes are demanded. Present results suggest that with the proposed method, the range of very low bit-rate can be achieved, maintaining a good subjective quality.

关键词： TREE SEGMENTATION MULTIRESOLUTION coding MULTIGRIDS MOTION ESTIMATION entropy coding

来源：评论

学校读者我要写书评

暂无评论

Adaptive grayscale image coding scheme based on dynamic multi-grouping absolute moment block truncation coding

引用

MULTIMEDIA TOOLS AND APPLICATIONS 2020年第37-38期79卷 28189-28205页

作者： Chuang, Jun-Chou Hu, Yu-Chen Chen, Chia-Mei Yin, Zhaoxia Providence Univ Dept Comp Sci & Commun Engn 200 Chung Chi Rd Taichung 43301 Taiwan Providence Univ Dept Comp Sci & Informat Management 200 Chung Chi Rd Taichung 43301 Taiwan Natl Sun Yat Sen Univ Dept Informat Management Kaohsiung 80424 Taiwan Anhui Univ Sch Comp Sci & Technol Key Lab Intelligent Comp & Signal Proc Minist Educ Hefei 230601 Peoples R China

Multi-Grouping Absolute Moment Block Truncation coding (MGAMBTC) technique improve the image quality of Absolute Moment Block Truncation coding (AMBTC) by adaptively dividing pixels in a block into groups according to block activity. This study found that the bit rate can be reduced further if there is some similarity among the blocks. Therefore, this study proposes a block prediction scheme that exploits the intra-block similarity of neighboring blocks. If a similar encoded block is found, its position code will be stored to encode the block;otherwise, it is encoded with the proposed improved MGAMBTC (iMGAMBTC). The proposed iMGAMBTC employs an entropy-based indicator generation mechanism to reduce the bit rate, and the evaluation demonstrates that the proposed scheme enhances the compression performance of AMBTC and MGAMBTC efficiently.

关键词： Image compression Absolute moment block truncation coding Adaptive pixel grouping Block prediction technique entropy coding

来源：评论

学校读者我要写书评

暂无评论

Application-Guided Power-Efficient Fault Tolerance for H.264 Context Adaptive Variable Length coding

引用

IEEE TRANSACTIONS ON COMPUTERS 2017年第4期66卷 560-574页

作者： Shafique, Muhammad Rehman, Semeen Kriebel, Florian Khan, Muhammad Usman Karim Zatt, Bruno Subramaniyan, Arun Vizzotto, Bruno Boessio Henkel, Joerg Vienna Univ Technol Embedded Comp Syst Grp A-1040 Vienna Austria Tech Univ Dresden A-1040 Vienna Austria IBM Res D-71032 Boblingen Germany Univ Fed Pelotas BR-96010610 Pelotas Brazil Univ Michigan Ann Arbor MI 48109 USA Univ Pampa BR-96412420 Bage RS Brazil Karlsruhe Inst Technol D-76131 Karlsruhe Germany

This paper presents a fault-tolerance technique for H.264's Context-Adaptive Variable Length coding (CAVLC) on unreliable computing hardware. The application-specific knowledge is leveraged at both algorithm and architecture levels to protect the CAVLC process (especially context adaptation and coding tables) in a reliable yet power-efficient manner. Specifically, the statistical analysis of coding syntax and video content properties are exploited for: (1) selective redundancy of coefficient/header data of video bitstreams;(2) partitioning the coding tables into various sub-tables to reduce the power overhead of fault tolerance;and (3) run-time power management of memory parts storing the sub-tables and their parity computations. Experimental results demonstrate that leveraging application-specific knowledge reduces area and performance overhead by 2x compared to a double-parity table protection technique. For functional verification and area comparison, the complete H.264 CAVLC architecture is prototyped on a Xilinx Virtex-5 FPGA (though not limited to it).

关键词： Application-specific optimization h.264 entropy coding video coding reliability fault tolerance

来源：评论

学校读者我要写书评

暂无评论

Efficient Fine-Granular Scalable coding of 3D Mesh Sequences

引用

IEEE TRANSACTIONS ON MULTIMEDIA 2013年第3期15卷 485-497页

作者： Ahn, Jae-Kyun Koh, Yeong Jun Kim, Chang-Su Korea Univ Sch Elect Engn Seoul South Korea

An efficient fine-granular scalable coding algorithm of 3-D mesh sequences for low-latency streaming applications is proposed in this work. First, we decompose a mesh sequence into spatial and temporal layers to support scalable decoding. To support the finest-granular spatial scalability, we decimate only a single vertex at each layer to obtain the next layer. Then, we predict the coordinates of decimated vertices spatially and temporally based on a hierarchical prediction structure. Last, we quantize and transmit the spatio-temporal prediction residuals using an arithmetic coder. We propose an efficient context model for the arithmetic coding. Experiment results show that the proposed algorithm provides significantly better compression performance than the conventional algorithms, while supporting finer-granular spatial scalability.

关键词： 3D mesh coding entropy coding fine-granular scalability mesh sequence compression predictive coding spatial layer decomposition.

来源：评论

学校读者我要写书评

暂无评论

GRAY-SCALE IMAGE-coding FOR FREEZE-FRAME VIDE-OCONFERENCING

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 1986年第4期34卷 382-394页

作者： ANASTASSIOU, D PENNEBAKER, WB MITCHELL, JL IBM CORP THOMAS J WATSON RES CTRYORKTOWN HTSNY 10598

A new gray-scale image coding technique has been developed, in which an extended DPCM approach has been combined with entropy coding. This technique has been implemented in a freeze-frame videoconferencing system which is now operational at IBM sites throughout the world. Following image preprocessing, the two fields of the interlaced 512 x 480 pixel video frame are compressed sequentially with different algorithms. The reconstructed image quality is improved by subsequent image postprocessing, the final reconstructed image being almost indistinguishable from the original image. Typical gray-scale video images compress to about a half bit per pixel and transmit over 4.8 kbit/s dial-up telephone lines in about a half minute. The gray-scale image processing and compression algorithms are described in this paper.

关键词： Gray-scale Image coding Teleconferencing Pixel Video compression Image reconstruction entropy coding Image quality Telephony Image processing

来源：评论

学校读者我要写书评

暂无评论

Adaptive lossless image coding using least squares optimization with edge-look-ahead

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS 2005年第11期52卷 751-755页

作者： Kau, LJ Lin, YP Natl Chiao Tung Univ Dept Elect & Control Engn Hsinchu 30010 Taiwan

In predictive image coding, the least squares (LS)-based adaptive predictor is noted as an efficient method to improve prediction result around edges. However pixel-by-pixel optimization of the predictor coefficients leads to a high coding complexity. To reduce computational complexity, we activate the LS optimization process only when the coding pixel is around an edge or when the prediction error is large. We propose a simple yet effective edge detector using only causal pixels. The system can look ahead to determine if the coding pixel is around an edge and initiate the LS adaptation to prevent the occurrence of a large prediction error. Our experiments show that the proposed approach can achieve a noticeable reduction in complexity with only a minor degradation in the prediction results.

关键词： adaptive prediction context modeling edge detection entropy coding least squares (LS) optimization lossless image coding

来源：评论

学校读者我要写书评

暂无评论

LineDiff entropy: Lossless Layout Data Compression Scheme for Maskless Lithography Systems

引用

IEEE SIGNAL PROCESSING LETTERS 2013年第7期20卷 645-648页

作者： Tang, Chin-Khai Su, Ming-Shing Lu, Yi-Chang Natl Taiwan Univ Grad Inst Elect Engn Taipei 10617 Taiwan QNAP Syst Inc Taipei 22161 Taiwan

This letter presents a new lossless electron-beam layout data compression and decompression algorithm named LineDiff entropy. The algorithm is designed to facilitate high volume data transfer and massively-parallel decompression in electron-beam direct-write lithography systems. LineDiff entropy first compares consecutive electron-beam data scanlines and encodes the data based on change/no-change of pixel values and length of corresponding sequences. Then LineDiff entropy utilizes the entropy encoding technique to assign unique short codes to data of frequent occurrence. Because the code format is simple and effective, LineDiff entropy decompression can be achieved with limited computing resources. The benchmark results show that LineDiff entropy is capable of achieving excellent compression factors and very fast decompression speed.

关键词： Circuit layout data compression electron-beam lithography entropy coding

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：