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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： K. Leung M. Jin Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA

Radarsat is an Earth observing SAR mission led by the Canadian Space Administration (CSA). NASA is participating as a partner and is responsible for the planning, processing, archiving and distribution of data collected at the Alaska SAR Facility (ASF). Among the five Radarsat operating modes, scan SAR represents a novel approach in data collection. The scanning beam data taking arrangement effectively acts like a burst mode radar allowing changing radar parameters from burst to burst much like the Venus mapping radar Magellan. With successive bursts 'scanned' from near to far range, swath coverage up to 500 km is achieved by properly combining images from these bursts. The paper presents a scan SAR data processor straw-man design that blueprints on the existing Magellan processing concept. Topics discussed include processing parameters derivation, signal compression algorithm selection, geometric rectification process and radiometric compensation strategy.< >

关键词： Radar imaging Earth Space missions NASA Process planning Venus Process design Signal processing compression algorithms Radiometry

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Application of the embedded wavelet hierarchical image coder to very low bit rate image coding

Application of the embedded wavelet hierarchical image coder...

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1993 IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： J.M. Shapiro The David Sarnoff Research Center SRI International Princeton NJ USA

The embedded wavelet hierarchical image coder is a simple and effective image compression algorithm, having the property that the bits in the bit stream are generated in order of importance, yielding a fully embedded code. An analysis of the algorithm is presented in which the embedded code is viewed as a sequence of binary decisions that distinguish an image from the 'null' image, i.e., the all-gray image. Thus the technique is similar in spirit to binary finite-precision representations of real numbers. An interesting application of very low-bit rate image coding, i.e., image database browsing, is discussed.< >

关键词： Bit rate Image coding Streaming media Discrete wavelet transforms Frequency Filters Rate distortion theory Decoding Tiles compression algorithms

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Mobile imagery systems using commercial technology

Mobile imagery systems using commercial technology

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MILCOM, Military Communications Conference

作者： K.A. Bouchard W.T. Brandon MITRE Corporation Bedford MA USA

Considerable improvement in satellite channel capacity utilization is achievable through application of compression technology to military communications, especially secondary imagery systems. Standards activities are producing uniform and powerful compression algorithms. In addition, the NITFS standardizes the format of digital imagery and imagery related data. NITFS incorporates JPEG and will incorporate other compression algorithms in the future.< >

关键词： compression algorithms Artificial satellites Military satellites Channel capacity Image coding Communications technology Military communication Standards activities Digital images Transform coding

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Rate distortion performance of VQ and PVQ compression algorithms

Rate distortion performance of VQ and PVQ compression algori...

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Data compression Conference (DCC)

作者： K.M. Liang S.E. Budge R.W. Harris Electrical Engineering Department Utah State University Logan UT USA

Summary form only given. This paper investigates the performance for memoryless sources and sources with memory by using vector quantization to encode and decode the source data. By modeling an image to be a Markov source, the authors suggest a lower bound estimate of the rate-distortion function for the image with memory which can be used to evaluate the performance of VQ (Vector Quantization) and predictive VQ. For the latter, the residual image, which is the difference between the original and the predictive image, is used to generate codebooks. In the encoder, three previous encoded pixels are used to predict the current pixels. The errors between a codevector and the corresponding predictive vector are compared and the minimum criterion is used to select the codevector.< >

关键词： Rate-distortion compression algorithms Vector quantization Decoding Rate distortion theory Predictive models Prediction algorithms Encoding

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PERFORMANCE ANALYSIS OF REVERSIBLE IMAGE compression TECHNIQUES FOR HIGH-RESOLUTION DIGITAL TELERADIOLOGY

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IEEE TRANSACTIONS ON MEDICAL IMAGING 1992年第3期11卷 430-445页

作者： KUDUVALLI, GR RANGAYYAN, RM Department of Electrical and Computer Engineering University of Calgary Calgary AB Canada Dept. of Electr. & Comput. Eng. Calgary Univ. Alta. Canada

In recent years, there have been a number of studies addressing both reversible and irreversible compression of medical images ranging from 256 x 256 to 2048 x 2048 pixels in spatial resolution. There is a need to address the high-resolution end of the image categories, namely mammograms and chest X-rays, which require resolution of the order of 4096 x 4096 pixels. Further, data compression schemes for most medical applications have to be information-preserving or reversible. In this paper, the performance of a number of block-based, reversible, compression algorithms suitable for compression of very large-format images (4096 x 4096 pixels or more) is compared to that of a novel two-dimensional linear predictive coder developed by extending the multichannel version of the Burg algorithm to two dimensions. The compression schemes implemented are: Huffman coding, Lempel-Ziv coding, arithmetic coding, two-dimensional linear predictive coding (in addition to the aforementioned one), transform coding using discrete Fourier-, discrete cosine-, and discrete Walsh transforms, linear interpolative coding, and combinations thereof. We discuss the performance of these coding techniques with a few mammograms and chest radiographs digitized to sizes up to 4096 x 4096, 10 b pixels. We have achieved compression from 10 bits to 2.5-3.0 b/pixel on these images without any loss of information. The modified multichannel linear predictor out-performs the other methods while offering certain advantages in implementation.

关键词： compression algorithms information loss pixel image compression method coding techniques(computer programming) Teleradiology compression

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A comparison of algorithms for ambulatory ECG compression with fixed average data rate

A comparison of algorithms for ambulatory ECG compression wi...

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Computers in Cardiology (CinC)

作者： P.S. Hamilton Lafayette College Easton PA USA

The author modified three electrocardiogram (ECG) data compression algorithms, average beat subtraction with residual differencing (ABSURD), SAPA compression, and TRIM compression, to produce specified average data rates. He tested the three algorithms on channel one of the MIT-BIH arrhythmia database sampled at 100 sample/s. With a target data rate of 193 b/s, average data rates for the SAPA and ABSURD algorithms varied from 99.7 to 100.1% of the target data rate. TRIM compression algorithms ranged from 87.3% to 101.7% of the target rate. With the average data rate controlled, ABSURD produced signal-to-compression noise ratios that ranged from 46 to 943. SAPA produced SNRs that ranged from 47 to 436, and TRIM produced SNRs that ranged from 54 to 806.< >

关键词： Electrocardiography Data compression compression algorithms Quantization Signal to noise ratio Solid state circuits Difference equations Educational institutions Testing Databases

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PRIORITIZATION AND TRANSPORT IN THE ADTV DIGITAL SIMULCAST SYSTEM

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IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 1992年第3期38卷 319-324页

作者： JOSEPH, K NG, S SIRACUSA, R RAYCHAUDHURI, D ZDEPSKI, J SAINTGIRONS, R THOMSON CONSUMER ELECTR LOS ANGELES RES & DEV LABCULVER CITYCA 90230 DAVID SARNOFF RES CTR BROADBAND COMMUN RES GRPPRINCETONNJ 08543

This paper provides a technical overview of the prioritization and transport in the Advanced Digital Television system (ADTV). ADTV is the all-digital terrestrial simulcast system developed by the Advanced Television Research Consortium, ATRC, (Thomson Consumer Electronics, Philips North America, NBC, compression Labs, and the David Sarnoff Research Center.) ADTV incorporates an efficient MPEG-compatible compression algorithm at its central core, with application-specific data prioritization and transport features added as separable layers. The compression process is based on a 1440x960 (1050-line 2:1 interlaced) HDTV format, producing a selectable bit-rate in the region of 15-20 Mbps. The data prioritization layer of ADTV achieves robust delivery over an appropriate two-tier modem by separating compressed video data into high- and standard-priority bitstreams with appropriate bit-rates. This prioritized data is then formatted into fixed length "cells" (packets) with appropriate data-link level and service-specific adaptation level headers, designed to provide capabilities such as flexible service multiplexing, priority handling, efficient cell packing, error detection and graceful recovery from errors. (Issues related to the ADTV compression coding, receiver error recovery, and transmission are discussed in separate papers.[1,2,3])

关键词： HDTV Video compression Transform coding Error correction Consumer electronics Robustness Digital TV compression algorithms Decoding Cities and towns

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Constraints on Variable Bit-Rate Video for ATM Networks

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1992年第4期2卷 361-372页

作者： Reibman, Amy R. Haskell, Barry G. AT&T Bell Labs Holmdel NJ 07733 USA

We consider constraints on the encoded bit rate of a video signal that are imposed by a channel and encoder and decoder buffers. We present conditions that ensure that the video encoder and decoder buffers do not overflow or underflow when the channel can transmit a variable bit rate. Using these conditions and a commonly proposed network-user contract, we examine the effect of a network policing function on the allowable variability in the encoded video bit rate. We describe how these ideas might be implemented in a system that controls both the encoded and transmitted bit rates. Finally, we present the performance of video that has been encoded using the derived constraints for the leaky bucket channel.

关键词： Bit rate Video compression Asynchronous transfer mode Decoding B-ISDN Control systems Contracts compression algorithms Algorithm design and analysis Streaming media

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HIGH-PERFORMANCE CODING SYSTEMS FOR DIGITAL TRANSMISSION OF TV AND HDTV SIGNALS

HIGH-PERFORMANCE CODING SYSTEMS FOR DIGITAL TRANSMISSION OF ...

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INTERNATIONAL BROADCASTING CONVENTION

作者： DUMENIL, P PERRON, C SCHWARTZ, P Thomson-CSF/LER France

ISBN: (纸本)0852965478

The studies performed in the framework of CMTT/2 for the transmission of 4:2:2 video signals through digital networks, have led to the definition of a bitrate reduction algorithm. In order to implement this videoalgorithm on a single board, a considerable effort has been made to develop an ASIC chipset, capable of processing 27 M samples per second (4:2:2 picture). For HDTV signals, the same technique can be used to provide a bitrate reduction from 1.152 Gbit/s to about 120 Mbit/s. This compression algorithm allows the transmission of one HDTV channel with audio and service channels on a 139.264 Mbit/s (or 2*34.368 Mbit/s) G703/G751 link or on an ATM network (155.5 Mbit/s). The authors describe the hardware implementation of the chipset in TV and HDTV codecs; emphasis is put to the features and performances of the equipment.

关键词： Digital transmission chip set Performance equipment Digital networks Coding systems compression algorithms Audio

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A Technique For Lossless compression Of Seismic Data

A Technique For Lossless Compression Of Seismic Data

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： S.D. Steams Sandia National Laboratories Albuquerque NM 87185.

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