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wavelets - Applications in Signal and Image Processing X Conference

作者： Kajita, T Kasai, K Saito, Y Fukuda, K Kawanaka, A Sophia Univ Fac Sci & Technol Chiyoda Ku Tokyo 1028554 Japan

ISBN: (纸本)0819450804

In order to compress 3-D shaped data, this paper presents an adaptive coding method using 2-D signal compression technique for the structured data on a 2-D plane, maintaining the adjacent relation of each vertex of the 3-D model. This structured data on a 2-D plane is not rectangular, so we apply Shape Adaptive wavelet Transform to compress the structured data on a 2-D plane. And we change the weight for wavelet coefficients adaptively for each frequency band, considering the normal vectors on the surface model rendering. The experiments show that the rendering characteristics can be improved by using the proposed method.

关键词： 3-D shape model polygonal mesh wavelet coding distortion of the normal vector weighting factor

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An efficient coding algorithm for the compression of ECG signals using the wavelet transform

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IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 2002年第4期49卷 355-362页

作者： Rajoub, BA Yarmouk Univ Dept Elect & Commun Engn Irbid 21163 Jordan

A wavelet-based electrocardiogram (ECG) data compression algorithm is proposed in this paper. The ECG signal is first preprocessed, the discrete wavelet transform (DWT) is then applied to the preprocessed signal. Preprocessing guarantees that the magnitudes of the wavelet coefficients be less than one, and reduces the reconstruction errors near both ends of the compressed signal. The DWT coefficients are divided into three groups, each group is thresholded using a threshold based on a desired energy packing efficiency. A binary significance map is then generated by scanning the wavelet decomposition coefficients and outputting a binary one if the scanned coefficient is significant, and a binary zero if it is insignificant. Compression is achieved by 1) using a variable length code based on run length encoding to compress the significance map and 2) using direct binary representation for representing the significant coefficients. The ability of the coding algorithm to compress ECG signals is investigated, the results were obtained by compressing and decompressing the test signals. The proposed algorithm is compared with direct-based and wavelet-based compression algorithms and showed superior performance. A compression ratio of 24:1 was achieved for MIT-BIH record 117 with a percent root mean square difference as low as 1.08%.

关键词： ECG compression energy packing efficiency thresholding wavelet coding

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Bitplane-by-bitplane shift (BbBShift) - A suggestion for JPEG2000 region of interest image coding

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IEEE SIGNAL PROCESSING LETTERS 2002年第5期9卷 160-162页

作者： Wang, Z Bovik, AC Univ Texas Dept Elect & Comp Engn Lab Image & Video Engn Austin TX 78712 USA

The JPEG2000 image coding standard defines two kinds of region of interest (ROI) coding methods-the general scaling based method and the maximum shift (maxshift) method. The former requires shape coding of the ROIs, which leads to increased complexity of codec implementations and limits the choice of ROI shapes (currently, only rectangle and ellipse shapes are defined). The latter allows for arbitrarily shaped ROI coding without explicitly transmitting any shape information to the decoder, but does not have the flexibility to select an arbitrary scaling value to define the relative importance of the ROI and the background wavelet coefficients. We propose a bitplane-by-bitplane shift (BbBShift) method, which supports both arbitrary ROI shape and arbitrary scaling without shape coding.

关键词： image coding JPEG2000 region of interest (ROI) bitplane coding wavelet coding maximum shift (maxshift) bitplane-by-bitplane shift (BbBShift)

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Arbitrary rate maximum-distance separable wavelet codes

Arbitrary rate maximum-distance separable wavelet codes

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IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Fekri, F Georgia Inst Technol Ctr Signal & Image Proc Atlanta GA 30332 USA

ISBN: (纸本)0780374029

This paper expands on the idea of wavelet coding. It undertakes construction of arbitrary rate error correcting codes using finite-field wavelets and filter banks. We show that a rate K/L code can be constructed by a combination of a K-band trivial analysis bank and an L-band synthesis bank. Several issues regarding these wavelet codes are investigated. Among other results, we develop a methodology to construct maximum-distance separable (MDS) codes using finite-field wavelets. In this method, a rate K/L code is constructed by a direct sum of the K rate 1/L subcodes which have been designed using the Bose-Chaudhuri-Hocquenghem (BCH) bound such that their direct sum generates an MDS code.

关键词： wavelet transforms transform coding error correction codes BCH codes channel bank filters arbitrary rate codes wavelet coding error correcting codes Bose-Chaudhuri-Hocquenghem bound BCH bound MDS code finite-field wavelets filter banks rate K/L code K-band trivial analysis bank L-band synthesis bank maximum-distance separable wavelet codes

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A tutorial on modern lossy wavelet image compression: Foundations of JPEG 2000

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IEEE SIGNAL PROCESSING MAGAZINE 2001年第5期18卷 22-35页

作者： Usevitch, BE Univ Texas Dept Elect & Comp Engn El Paso TX 79968 USA

One of the purposes of this article is to give a general audiencesufficient background into the details and techniques of wavelet codingto better understand the JPEG 2000 standard. The focus is on thefundamental principles of wavelet coding and not the actual standarditself. Some of the confusing design choices made in wavelet coders areexplained. There are two types of filter choices: orthogonal andbiorthogonal. Orthogonal filters have the property that there are energyor norm preserving. Nevertheless, modern wavelet coders use biorthogonalfilters which do not preserve energy. Reasons for these specific designchoices are explained. Another purpose of this article is to compare andcontrast “early” wavelet coding with “modern”wavelet coding. This article compares the techniques of the modernwavelet coders to the subband coding techniques so that the reader canappreciate how different modern wavelet coding is from early waveletcoding. It discusses basic properties of the wavelet transform which arepertinent to image compression. It builds on the background material ingeneric transform coding given, shows that boundary effects motivate theuse of biorthogonal wavelets, and introduces the symmetric wavelettransform. Subband coding or “early” wavelet coding methodis discussed followed by an explanation of the EZW coding *** modern wavelet coders that extend the ideas found in the EZWalgorithm are also described

关键词： code standards filtering theory image coding linear phase filters telecommunication standards transform coding wavelet transforms EZW coding algorithm JPEG 2000 standard biorthogonal filters biorthogonal wavelets boundary effects early wavelet coding mod Image compression wavelets filtering theory transform coding linear phase filters wavelet transforms border effects code standards image coding Data compression Modulo ENCODER biorthogonal wavelet wavelet coding biorthogonal filter

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Significance-linked connected component analysis for very low bit-rate wavelet video coding

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1999年第4期9卷 630-647页

作者： Vass, J Chai, BB Palaniappan, K Zhuang, X Univ Missouri Multimedia Commun & Visualizat Lab Dept Comp Engn & Comp Sci Columbia MO 65211 USA Sarnoff Corp Princeton NJ 08543 USA

In recent years, a tremendous success in wavelet image coding has been achieved. It is mainly attributed to innovative strategies for data organization and representation of wavelet-transformed images. However, there hare been only a few successful attempts in wavelet video coding. The most successful is perhaps Sarnoff Corp.'s zerotree entropy (ZTE) video coder, In this paper, a novel hybrid wavelet video coding algorithm termed video significance-linked connected component analysis (VSLCCA) is developed for very low hit-rate applications. There also has been empirical evidence that wavelet transform combined with those innovative data organization and representation strategies can be an invaluable asset in very low bit-rate video coding as long as motion compensated error frames are ensured to be free of blocking effect or coherent, In the proposed VSLCCA codec, first, fine-tuned motion estimation based on the H.263 Recommendation is developed to reduce temporal redundancy, and exhaustive overlapped block motion compensation is utilized to ensure coherency in motion compensated error frames. Second, wavelet transform is applied to each coherent motion compensated error frame to attain global energy compaction. Third, significant fields of wavelet-transformed error frames are organized and represented as significance-linked connected components so that both the within-subband clustering and the cross-scale dependency are exploited, Last, the horizontal and vertical components of motion vectors are encoded separately using adaptive arithmetic coding while significant wavelet coefficients are encoded in bit-plane order by using high order Markov source modeling and adaptive arithmetic coding, Experimental results on eight standard MPEG-4 test sequences show that for intraframe coding, on average the proposed codec exceeds H.263 and ZTE in peak signal-to-noise ratio by as much as 2.07 and 1.38 dB at 28 kbits, respectively. For entire sequence coding, VSLCCA is superio

关键词： data organization and representation motion compensation motion estimation video coding wavelet coding

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Rate-scalable object-based wavelet codec with implicit shape coding

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2000年第7期10卷 1068-1079页

作者： Kassim, AA Zhao, LF Natl Univ Singapore Dept Elect Engn Singapore 119260 Singapore

In this paper, we present an embedded approach for coding image regions with arbitrary shapes. Our scheme takes a different approach by separating the objects in the transform domain instead of the image domain so that only one transform for the entire image is required. We define a new shape-adaptive embedded zerotree wavelet coding (SA-EZW) technique for encoding the coefficients corresponding to specific objects in gray-scale and color-image segments by implicitly representing their shapes, thereby forgoing the need for separately coding the region boundary, At our decoder, the shape information can be recovered without separate and explicit shape coding. The implicit shape coding enables the bit stream for the object to be fully rate scalable, since no explicit bit allocation is needed for the object shape. This makes it particularly suitable when content-based functionalities are desired in situations where the user bit rate is constrained and enables precise bit-rate control while avoiding the problem of contour coding. We show that our algorithm sufficiently addresses the issue of content-based scalability and improved coding efficiency when compared with the "chroma keying" technique, an implicit shape-coding technique which is adopted by the current MPEG-4 standard.

关键词： coefficient selection content based implicit shape coding low bit rate coding region based wavelet coding zerotree

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Efficient methods for encoding regions of interest in the upcoming JPEG2000 still image coding standard

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IEEE SIGNAL PROCESSING LETTERS 2000年第9期7卷 247-249页

作者： Christopoulos, C Askelöf, J Larsson, M Ericsson Radio Syst AB Ericsson Res Corp Unit Stockholm Sweden

The general method for generating the regions of interest (ROI) mask needed for encoding ROI in the upcoming JPEG2000 still image coding standard is presented. A simple method for the generation of the ROI mask for rectangular-shaped ROI is then proposed. Finally to simplify the decoder when dealing with arbitrary shaped ROIs, a method for ROI coding that does not require any shape information to be transmitted to the decoder is described. A small coding penalty is associated with this method, while it makes it possible to have arbitrarily shaped ROI without the need of shape information and ROI mask generation at the decoder. The proposed methods have been included in the Final Committee Draft of JPEG2000 Part I.

关键词： JPEG2000 regions of interest (ROI) wavelet coding

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An analysis on the effect of image features on lossy coding performance

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IEEE SIGNAL PROCESSING LETTERS 2000年第5期7卷 104-107页

作者： Saha, S Vemuri, R Univ Calif Davis Davis CA 95616 USA

When a variety of multimedia images of different types (natural, synthetic, compound, medical, etc.) are compressed using a fixed wavelet filter, it is observed that the peak SNR (PSNR) values for a given compression ratio vary widely by as much as 30 dB from image to image. In this letter, it is shown that most of the gray-level histogram statistics of the images do not have any direct effect on the lossy coding performance, and image activity measure (IAM) is the only feature that has a negative correlation with the PSNR value We determine the best measure of such image activity and show that one of these IAM's is not only very effective in differentiating between various images but also correlates well with the PSNR, We establish this relationship in the form of the IAM-PSNR equation.

关键词： IAM-PSNR equation image activity measure image statistics peak signal-to-noise ratio (PSNR) wavelet coding

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Prediction-based lower triangular transform

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2000年第7期48卷 1947-1955页

作者： Phoong, SM Lin, YP Natl Taiwan Univ Inst Commun Engn Dept Elect Engn Taipei 10764 Taiwan Natl Chiao Tung Univ Dept Elect & Control Engn Hsinchu 30039 Taiwan

In this paper, a new nonunitary transform called the prediction-based lower triangular transform (PLT) is introduced for signal compression. The new transform has the same decorrelation property as the Kahurnen-Loeve transform (KLT), but its implementational cost is less than one half of KLT, Compared with the KLT, the design cost of an M x M PLT is much lower and is only of the order of O(M-2). Moreover, the PLT can be factorized into simple building blocks, Using two different factorizations, we introduce two minimum noise structures that have roughly the same complexity as the direct implementation of PLT. These minimum noise structures have the following properties: 1) Its noise gain is unity even though the transform is nonunitary;2) perfect reconstruction is structurally guaranteed;3) it can be used for both. lossy/lossless compression. We will show that the coding gain of PLT implemented using the minimum noise structure is the same as that of KLT. Furthermore, universal transform coders using PLT are derived. For AR(1) process, the M x M PLT has a closed form and needs only (M - 1) multiplications and additions.

关键词： compression Karhunen-Loeve transform (KLT) subband coding transform coding wavelet coding

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