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LOSSLESS COMPRESSION OF MEDICAL IMAGES BY PREDICTION AND CLASSIFICATION

OPTICAL ENGINEERING 1994年第1期33卷 160-166页

作者： LEE, HS KIM, YM OH, SH UNIV WASHINGTON DEPT ELECT ENGNIMAGE COMP SYST LABSEATTLEWA 98195

A lossless image compression algorithm based on a prediction and classification scheme is presented. The algorithm decomposes an image into four subimages by subsampling pixels at even and odd (both row and column) locations. Because the four subimages have strong correlations to one another, one of them is used as a reference in predicting the other three, and the resulting differences between the predicted subimages and the original subimages are encoded. Even though these differences are decorrelated and tend to be random, there is still a relatively large correlation left between the estimated differences and the subimage used in prediction. For example, the estimated differences tend to be large in a high-detailed region, where pixel values change rapidly, whereas the differences are small in a low-detailed region, where pixel values change smoothly and slowly. This redundancy is exploited by dividing the estimated differences into subsets based on a slope change in the subimage used in prediction. The performance of the proposed algorithm using two different predictors, linear interpolation and third-order polynomial interpolation, is compared with that of the hierarchical interpolation (HINT) scheme and Fourier transform interpolation by measuring the first-order entropies of the estimated differences. With a third-order polynomial interpolation and division into two subsets, an average entropy of 3.1 bits/pixel is achieved for the three predicted difference subimages of the 12 bits/pixel x-ray computed tomography images. It is about 0.86 bits/pixel lower in the first-order entropy than the HINT for the three subimages.

关键词： LOSSLESS COMPRESSION PIXEL CLASSIFICATION differential coding COMPUTED TOMOGRAPHY IMAGE COMPRESSION

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An application of the differential spread-spectrum technique in mobile underwater acoustic communication

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Science China(Information Sciences) 2011年第10期54卷 2190-2198页

作者： YIN JingWei,ZHANG Xiao,SUN LiQiang & MEI JiDan Harbin Engineering University,Science and Technology on Underwater Acoustic Laboratory,Harbin 150001,China 1. Science and Technology on Underwater Acoustic Laboratory Harbin Engineering University Harbin 150001 China

A direct sequence/binary differential phase-shift keying underwater acoustic communication technique based on differential coherent demodulation is *** coherent demodulation is adopted at the receiving terminal to overcome the difficulty of estimating the carrier in underwater acoustic communication and overcoming the frequency and phase error resulting from carrier frequency ***-multipath,antiDoppler,low-error-rate,effective and robust features for a complex underwater acoustic channel were verified in a lake experiment.

关键词： Doppler differential coding spread spectrum communication underwater acoustic communication

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Performance of coded modulation employing differential encoding over Rayleigh fading channels

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ELECTRONICS LETTERS 1999年第2期35卷 122-123页

作者： Fischer, RFH Calabrò, S Lampe, LHJ Müller-Weinfurtner, SH Univ Erlangen Nurnberg Lab Nachrichtentech D-91058 Erlangen Germany Univ Palermo Dipartimento Ingn Elettr Palermo Italy

Multilevel coding and bit-interleaved coded modulation employing differential encoding and non-coherent reception over flat fading channels are assessed. To achieve high bandwidth efliciencies mixed amplitude/phase modulation is performed. It is shown that multiple symbol detection only provides gains for multilevel coding as Gray labelling of the differential symbols is not possible.

关键词： Signal encoding Communication channels (information theory) Rayleigh fading Bandwidth Gray labelling Bit-interleaved coded modulation Raleigh fading channels Bandwidth differential coding Rayleigh fading Multilevel coding bandwidth efficiency Signal encoding modulation coding Bit interleaved coded modulation flat fading channel

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differentialLY ENCODED M-PSK BLOCK-CODES

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IEEE TRANSACTIONS ON COMMUNICATIONS 1995年第9期43卷 2426-2428页

作者： SAYEGH, S HEMMATI, F COMSAT Laboratories Clarksburg MD USA

Two schemes for differential encoding of block-coded M-ary PSK signals are presented and compared. Both proposed schemes perform differential encoding after channel decoding for minimizing the performance penalty associated with differential schemes. The first scheme requires the block codes to be rotationally invariant and linear, whereas the second requires rotational invariance only, Examples of bit error fate performance are also presented.

关键词： Scheme differential coding bit error rate performance multiple phase shift keying Channel Decoder Block codes

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Zipper: A compact connectivity data structure for triangle meshes

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COMPUTER-AIDED DESIGN 2013年第2期45卷 262-269页

作者： Gurung, Topraj Luffel, Mark Lindstrom, Peter Rossignac, Jarek Georgia Inst Technol Atlanta GA 30332 USA Lawrence Livermore Natl Lab Livermore CA USA

We propose Zipper, a compact representation of incidence and adjacency for manifold triangle meshes with fixed connectivity. Zipper uses on average only 6 bits per triangle, can be constructed in linear space and time, and supports all standard random-access and mesh traversal operators in constant time. Similarly to the previously proposed LR (Laced Ring) approach, the Zipper construction reorders vertices and triangles along a nearly Hamiltonian cycle called the ring. The 4.4x storage reduction of Zipper over LR results from three contributions. (1) For most triangles, Zipper stores a 2-bit delta (plus three additional bits) rather than a full 32-bit reference. (2) Zipper modifies the ring to reduce the number of exceptional triangles. (3) Zipper encodes the remaining exceptional triangles using 2.5x less storage. In spite of these large savings in storage, we show that Zipper offers comparable performance to LR and other data structures in mesh processing applications. Zipper may also serve as a compact indexed format for rendering meshes, and hence is valuable even in applications that do not require adjacency information. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： Triangle meshes Mesh connectivity Hamiltonian cycle differential coding

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A simple lossless compression heuristic for grey scale images

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INTERNATIONAL JOURNAL OF FOUNDATIONS OF COMPUTER SCIENCE 2005年第6期16卷 1111-1119页

作者： Cinque, L De Agostino, S Liberati, F Westgeest, B Univ Roma La Sapienza Dept Comp Sci I-00198 Rome Italy Armstrong Atlantic State Univ Dept Comp Sci Savannah GA 31419 USA

In this paper, we show a simple lossless compression heuristic for gray scale images. The main advantage of this approach is that it provides a highly parallelizable compressor and decompressor. In fact, it can be applied independently to each block of 8x8 pixels, achieving 80 percent of the compression obtained with LOCO-I (JPEG-LS), the current lossless standard in low-complexity applications. The compressed form of each block employs a header and a fixed length code, and the sequential implementations of the encoder and decoder are 50 to 60 percent faster than LOCO-I.

关键词： grey scale image lossless compression differential coding parallelization

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An Efficient Reference Frame Compression Approach for Video coding Systems

An Efficient Reference Frame Compression Approach for Video ...

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IEEE 5th Latin American Symposium on Circuits and Systems (LASCAS)

作者： Povala, Guilherme Silveira, Dieison Amaral, Lvia Zatt, Bruno Porto, Marcelo Agostini, Luciano Univ Fed Pelotas Grad Program Comp Sci PPGC Grp Architectures & Integrated Syst GACI Capao Do Leao RS Brazil

ISBN: (纸本)9781479925070

This paper presents an efficient solution for external memory bandwidth reduction focusing in the state-of-art video coding standards, like H.264/AVC and HEVC. The proposed approach is based in reference frame compression using a differential coding and a hardware-efficiently adaptation of the traditional Huffman algorithm, besides, it is a lossless solution and fully complied to state-of-art video coding standards. This solution is entitled DRFVLC (differential Reference Frame Variable-Length Coder) and it applies an inter-block differential coding to concentrate the values near to zero, and also, it uses one static Huffman table to avoid the cost of the on-the-fly Huffman statistical analysis. The use of DRFVLC reached an average compression rate higher than 46% for the evaluated video sequences, with computational cost of a single differential coding and a VLC, which means the solution is not a bottleneck of the video coding system.

关键词： Video coding Memory bandwidth reduction Reference frame compression Huffman coding differential coding

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Color Image Authentication and Recovery via Adaptive Encoding

Color Image Authentication and Recovery via Adaptive Encodin...

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International Symposium on Computer, Consumer and Control (IS3C)

作者： Chen, Chun-Hung Tang, Yuan-Liang Hsieh, Wen-Shyong NSYSU Dept CSE Taipei Taiwan CYUT Dept IM Taipei Taiwan STU Dept CSIE Taipei Taiwan

ISBN: (纸本)9781479952779

In this paper, we describe an authentication and recovery scheme for color image protection based on adaptive encoding. The image blocks are categorized based on their contents and different encoding schemes are applied according to their types. Such adaptive encoding results in better image quality and more robust image authentication. The approximations of the luminance and chromatic channels are carefully calculated, and for the purpose of reducing the data size, the differential coding is used to encode the channels with variable size according the characteristic of the block. The recovery data which represents the approximation and the detail of the image is embedded for data protection. The necessary data is well protected by using the error correcting coding (ECC) and duplication. The experimental results demonstrate that our technique is able to identify and localize image tampering, while preserving high quality for both watermarked and recovered images.

关键词： image authentication digital watermarking fragile watermarks vector quantization differential coding

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INTRA PREDICTION MODE coding FOR SCALABLE HEVC

INTRA PREDICTION MODE CODING FOR SCALABLE HEVC

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

作者： Bugdayci, D. Bici, M. O. Ugur, K. Gabbouj, M. Tampere Univ Technol FIN-33101 Tampere Finland Nokia Res Ctr Tampere Finland

ISBN: (纸本)9781479903566

High Efficiency Video coding (HEVC) standard introduced an increased number of intra prediction directions in order to improve intra prediction performance by efficiently modeling the directional structures found in typical video contents. Efficient coding of intra prediction mode information is realized through a Most Probable Mode (MPM) list approach. In a scalable system, due to high correlation between the layers, utilization of base layer intra prediction mode can improve coding performance. In this paper, we propose a new intra prediction mode coding algorithm for scalable extension of HEVC where only the difference between the intra prediction modes of base and enhancement layers is coded. We provide experimental results and also a comparison of the proposed algorithm with an MPM list based approach where base layer intra prediction mode is added to the list as the most probable mode. Experimental results show BD-rate gains up to 1.1% in 2x spatial scalability and 0.7% in 1.5x scalability for all intra configuration.

关键词： HEVC video coding scalable intra prediction mode differential coding

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Undersampled Frequency Shift ON-OFF Keying (UFSOOK) for Camera Communications (CamCom)

Undersampled Frequency Shift ON-OFF Keying (UFSOOK) for Came...

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22nd Wireless and Optical Communications Conference (WOCC)

作者： Roberts, Richard D. Intel Corp Intel Labs Hillsboro OR 97124 USA

ISBN: (纸本)9781467356978;9781467356992

Camera communications is the use of an image sensor to receive LED modulated data. This paper shows how frequency shift ON-OFF keying - at frequencies that avoid flicker - can be used to encode bits while at the same time being successfully decoded by a low frame rate camera using subsampling. This is done by selecting mark and space frequencies that are harmonics of the camera frame rate and then processing the subsampled aliased frequencies to decode bit data.

关键词： camera communications frequency shift keying ON-OFF keying undersampling visible light communications LED image sensor aliasing differential coding OOK FSK VLC UFSOOK CamCom

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