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Performance analysis of a new semiorthogonal spline wavelet compression algorithm for tonal medical images

MEDICAL PHYSICS 2000年第2期27卷 276-288页

作者： Thompson, SK Hazle, JD Schomer, DF Elekes, AA Johnston, DA Huffman, J Chui, CK Univ Texas MD Anderson Canc Ctr Div Diagnost Imaging Houston TX 77030 USA Houston Adv Res Ctr The Woodlands TX 77381 USA Univ Texas MD Anderson Canc Ctr Dept Biomath Houston TX 77030 USA Silicon Graph Inc Mt View CA 94043 USA Texas A&M Univ Ctr Approximat Theory College Stn TX 77843 USA

Lossy image compression is thought to be a necessity as radiology moves toward a filmless environment. compression algorithms based on the discrete cosine transform (DCT) are limited due to the infinite support of the cosine basis function. Wavelets, basis functions that have compact or nearly compact support, are mathematically better suited for decorrelating medical image data. A lossy compression algorithm based on semiorthogonal cubic spline wavelets has been implemented and tested on six different image modalities (magnetic resonance, x-ray computed tomography, single photon emission tomography, digital fluoroscopy, computed radiography, and ultrasound). The fidelity of the reconstructed wavelet images was compared to images compressed with a DCT algorithm for compression ratios of up to 40:1. The wavelet algorithm was found to have generally lower average error metrics and higher peak-signal-to-noise ratios than the DCT algorithm. (C) 2000 American Assiciation of Physicists in Medicine. [S0094-2405(00)02001-0].

关键词： algorithms Diagnostic Imaging 算法诊断显像 compression ratio discrete cosine transforms wavelets image data spline wavelet lossy image compression lossy compression diagnostic imaging compression algorithms DCT gene Radiology single photon emission computed tomography algorithms basis functions

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An approximation to the greedy algorithm for differential compression

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IBM JOURNAL OF RESEARCH AND DEVELOPMENT 2006年第1期50卷 149-166页

作者： Agarwal, RC Gupta, K Jain, S Amalapurapu, S IBM Corp Almaden Res Ctr Div Res San Jose CA 95120 USA Harvard Univ Div Engn & Appl Sci Cambridge MA 02138 USA Motorola Inc Sunnyvale CA 95089 USA

We present a new differential compression algorithm that combines the hash value techniques and suffix array techniques of previous work. The term '' differential compression '' refers to encoding a file (a version file) as a set of changes with respect to another file (a reference file). Previous differential compression algorithms can be shown empirically to run in linear time, but they have certain drawbacks;namely, they do not find the best matches for every offset of the version file. Our algorithm, hsadelta (hash suffix array delta), finds the best matches for every offset of the version file, with respect to a certain granularity and above a certain length threshold. The algorithm has two variations depending on how we choose the block size. We show that if the block size is kept fixed, the compression performance of the algorithm is similar to that of the greedy algorithm, without the associated expensive space and time requirements. If the block size is varied linearly with the reference file size, the algorithm can run ill linear time and constant space. We also show empirically that the algorithm performs better than other state-of-the-art differential compression algorithms in terms of compression and is comparable in speed.

关键词： compression algorithms greedy algorithm benzoylprop-ethyl algorithms hashing Suffix

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Switching between two on-line list update algorithms for higher compression of Burrows-Wheeler transformed data

Switching between two on-line list update algorithms for hig...

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Data compression Conference (DCC)

作者： B. Chapin Department of Computer Science University of North Texas Denton TX USA

Encoding data by switching between two universal data compression algorithms achieves higher rates of compression than either algorithm alone. Applied with two list updating algorithms, the technique yields higher compression of piecewise independent identically distributed (PIID) data, such as the output of the Burrows-Wheeler transform. Introduced within a new class of such algorithms, the Best x of 2x-1. When paired with variants of the move-to-front algorithm in a switching scheme, the Best x of 2x-1 algorithms achieve higher compression of PIID data.

关键词： Cost function Encoding Entropy Switches Sequences Computer science Data compression compression algorithms Electronic mail Algorithm design and analysis

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compression-coded genetic algorithms and its application in traffic control

Compression-coded genetic algorithms and its application in ...

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International Conference on Machine Learning and Cybernetics (ICMLC)

作者： Yan-Ke Shi Zhong-Ke Shi Institute of Air Traffic Management Northwestern Polytechnical University Xi'an China

The compression coding, generated by suitable compressing method, is applied in a genetic algorithm. Its length, together with its corresponding length of the non-compressed coding, can be altered. As one compression-code bit is ordinarily on behalf of several non-compressed bits, changes in any compression-code bit will create changes in several non-compressed ones. Therefore, the compression-coded genetic algorithm is helpful to improve the diversity of the model and the parallelism of the algorithms. In practice, according to the constrict condition and a self-adaptive decoding function, the compressed code genetic algorithm can avoid a premature convergence of the evaluation of multi-extremum in genetic algorithms in some degrees, therefore improve the search capacity of the global optimal solution. Through the multiobjective optimization by applying the compression coding genetic algorithms on the basis of the dynamic multi-driveway four-phase network model of urban traffic, the simulation result is confirmed to be feasible.

关键词： Genetic algorithms Traffic control Decoding Communication system traffic control Particle separators compression algorithms Air traffic control Testing Cities and towns Control systems

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algorithms and architectures for hierarchical compression of video

Algorithms and architectures for hierarchical compression of...

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International Conference on Application Specific Array Processors

作者： M. Vishwanath Computer Science Lab Xerox-PARC Palo Alto CA USA

The paper addresses the problem of collaborative video over "heterogeneous" networks. Current standards for video compression are not designed to deal with this problem. We define an additional set of metrics (ie., in addition to the standard rate versus distortion measure) to evaluate compression algorithms for this application. We also present an efficient algorithm and corresponding architectures for video compression in such an environment. The algorithm is a unique combination of the discrete wavelet transform and hierarchical vector quantization. It is unique in that both the encoder and the decoder are implemented with only table lookups. This makes both the software and hardware implementations very efficient and cheap.< >

关键词： Video compression Discrete wavelet transforms Collaboration Measurement standards Rate distortion theory Distortion measurement compression algorithms Computer architecture Vector quantization Decoding

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algorithms and Hardware Structures for Unobtrusive Real-Time compression of Instruction and Data Address Traces

Algorithms and Hardware Structures for Unobtrusive Real-Time...

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Data compression Conference (DCC)

作者： Milena Milenkovic Aleksandar Milenkovic Martin Burtscher IBM Austin TX USA Electrical and Computer Engineering Department University of Alabama Huntsville USA Computer Systems Laboratory Cornell University Ithaca NY USA

Instruction and data address traces are widely used by computer designers for quantitative evaluations of new architectures and workload characterization, as well as by software developers for program optimization, performance tuning, and debugging. Such traces are typically very large and need to be compressed to reduce the storage, processing, and communication bandwidth requirements. However, preexisting general-purpose and trace-specific compression algorithms are designed for software implementation and are not suitable for runtime compression. Compressing program execution traces at runtime in hardware can deliver insights into the behavior of the system under test without any negative interference with normal program execution. Traditional debugging tools, on the other hand, have to stop the program frequently to examine the state of the processor. Moreover, software developers often do not have access to the entire history of computation that led to an erroneous state. In addition, stepping through a program is a tedious task and may interact with other system components in such a way that the original errors disappear, thus preventing any useful insight. The need for unobtrusive tracing is further underscored by the development of computer systems that feature multiple processing cores on a single chip. In this paper, we introduce a set of algorithms for compressing instruction and data address traces that can easily be implemented in an on-chip trace compression module and describe the corresponding hardware structures. The proposed algorithms are analytically and experimentally evaluated. Our results show that very small hardware structures suffice to achieve a compression ratio similar to that of a software implementation of gzip while being orders of magnitude faster. A hardware structure with slightly over 2 KB of state achieves a compression ratio of 125.9 for instruction address traces, whereas gzip achieves a compression ratio of 87.4. For data addr

关键词： Hardware Algorithm design and analysis Runtime Computer aided instruction Computer architecture Software debugging Software performance Design optimization Bandwidth compression algorithms

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Efficient algorithms for the compression of FASTQ files

Efficient algorithms for the compression of FASTQ files

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IEEE International Conference on Bioinformatics and Biomedicine (BIBM)

作者： Subrata Saha Sanguthevar Rajasekaran Department of Computer Science and Engineering University of Connecticut Storrs

Since the introduction of the Sanger sequencing technology in 1977 by Frederic Sanger and his colleagues, we observe an explosion of sequence data. The cost of storage, processing, and analyzing the data is getting excessively high. As a result, it is extremely important that we develop efficient data compression and data reduction techniques. But standard data compression tools are not suitable to compress biological data since they contain many repetitive regions. There could exist high similarities among the sequences. In this context we need specialized algorithms to effectively compress biological data. In this paper we propose novel algorithms for compressing FASTQ files. We have done extensive and rigorous experiments that reveal that our proposed algorithm is indeed competitive and performs better than the best known algorithms for this problem.

关键词： Bioinformatics Genomics Sequential analysis Clustering algorithms compression algorithms Encoding Data compression

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Prototyping of efficient hardware algorithms for data compression in future communication systems

Prototyping of efficient hardware algorithms for data compre...

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International Workshop on Rapid System Prototyping (RSP)

作者： A. Mukherjee N. Motgi J. Becker A. Friebe C. Habermann M. Glesner Department of Computer Science University of Central Florida Orlando FL USA Institute of Microelectronic Systems Darmstadt University of Technology Darmstadt Germany

ISBN: (纸本)0769512062

Due to the high bandwidth requirements of up to 2 Mbit/s in 3rd-generation mobile communication systems, efficient data compression approaches are necessary to reduce communication and storage costs. The status of recent VLSI technologies promises complete system-on-a-chip (SoC) solutions for both mobile and network-based communication systems, including new compression algorithms based on the Burrows-Wheeler transform (BWT). The most complex task of the BWT algorithm is its lexicographic sorting of n cyclic rotations of a given string of n characters. This paper discusses the feasibility and VLSI implementation of this scalable BWT architecture in simulating and prototyping its systolic, highly utilized hardware structure with Virtex FPGAs.

关键词： Prototypes Hardware Data compression Mobile communication Very large scale integration System-on-a-chip Bandwidth Costs compression algorithms Sorting

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compression artifacts reduction using variational methods : algorithms and experimental study

Compression artifacts reduction using variational methods : ...

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

作者： Pierre Weiss Laure Blanc-Feraud Thomas Andre Marc Antonini Ariana Reseach Group INRIA/I3S CNRS Sophia-Antipolis France Creative project I3S CNRS/UNSA Sophia-Antipolis France

Many compression algorithms consist of quantizing the coefficients of an image in a linear basis. This introduces compression noise that often look like ringing. Recently some authors proposed variational methods to reduce those artifacts. They consists of minimizing a regularizing functional in the set of antecedents of the compressed image. In this paper we propose a fast algorithm to solve that problem. Our experiments lead us to the conclusion that these algorithms effectively reduce oscillations but also reduce contrasts locally. To handle that problem, we propose a fast contrast enhancement procedure. Experiments on a large dataset suggest that this procedure effectively improves the image quality at low bitrates.

关键词： Image coding Bit rate Transform coding compression algorithms Image quality Image restoration Optimization methods Wavelet transforms Image converters Convergence

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compression of multichannel ECG through multichannel long-term prediction

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IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE 1998年第1期17卷 109-115页

作者： Cohen, A Zigel, Y Ben Gurion Univ Negev Dept Elect & Comp Engn IL-84105 Beer Sheva Israel

The need for efficient coding of ECG signals is continually increasing with modern use of long-term monitoring and telemedicine. Here, the authors present an algorithm based on long-term prediction (LTP) compression. The single-channel LTP algorithm has been generalized to the multichannel case and is called the MC-LTP algorithm. This algorithm compresses PQRST beats using a pattern codebook with "typical" beats.

关键词： Electrocardiography Distortion measurement Predictive models Vectors Biomedical engineering Autocorrelation Modems Monitoring Telemedicine compression algorithms

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