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MINLAB: Minimum noise structure for ladder-based biorthogonal filter banks

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2000年第2期48卷 465-476页

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

In this paper, we introduce a minimum noise structure for ladder-based biorthogonal (MINLAB) filter bank. The minimum noise structure ensures that the quantization error has a unity noise gain, even though the filter bank is biorthogonal, The coder has a very low design and implementation cost. Perfect reconstruction property is structurally preserved, Optimal bit allocation and coding gain formulas are derived, We show that the coding gain of the optimal MINLAB coder is always greater than or equal to unity, For both AR(1) process and MA(1) process, the MINLAB coder with two taps has a higher coding gain than the optimal orthonormal coder with an infinite number of taps, In addition to its superior decorrelation ability, it has many other desired features that make it a potentially valuable and attractive alternative to the orthonormal coder, especially for the high-fidelity compression.

关键词： biorthogonal compression filter bank minimum noise subband coding wavelet coding

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A new class of optimal biorthogonal subband coder

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IEEE SIGNAL PROCESSING LETTERS 1999年第1期6卷 4-7页

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

In this letter, we introduce a novel two-channel biorthogonal subband coder. The new coder employs the ladder structure (or so-called wavelet with lifting scheme). The coding gain of the biorthogonal coder is always greater than or equal to unity, and it can be expressed in closed form. Moreover the proposed coder has a very low complexity and the perfect reconstruction property is structurally preserved. Given any filter order, the optimal solution can be found by the well-known Levinson fast algorithm. For both AR(1) process and MA(1) process, the proposed biorthogonal coder with 2 taps has a higher coding than the optimal orthonormal coder with infinite number of taps.

关键词： compression optimal coder subband coding wavelet coding

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WaveGuide: A joint wavelet-based image representation and description system

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IEEE TRANSACTIONS ON IMAGE PROCESSING 1999年第11期8卷 1619-1629页

作者： Liang, KC Kuo, CCJ Sharp Microelect Amer Huntington Beach CA 92647 USA Univ So Calif Integrated Media Syst Ctr Los Angeles CA 90089 USA Univ So Calif Dept Elect Engn Syst Los Angeles CA 90089 USA

Data representation and content description are two basic components required by the management of any image database. A wavelet-based system, called the WaveGuide, which integrates these two components in a unified framework, is proposed in this work. In the WaveGuide system, images are compressed with the state-of-the-art wavelet coding technique and indexed with color, texture, and object shape descriptors generated in the wavelet domain during the encoding process. All the content descriptors are extracted by machines automatically with a low computational complexity and stored with a low memory space. Extensive experiments are performed to demonstrate the performance of the new approach.

关键词： data compression image description image indexing image representation image retrieval wavelet coding

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Object based wavelet compression using coefficient selection

Object based wavelet compression using coefficient selection

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Meeting on Visual Communications and Image Processing

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

ISBN: (纸本)0819431249

In this paper, we present a novel approach to code image regions of arbitrary shapes. The proposed algorithm combines a coefficient selection scheme with traditional wavelet compression for coding arbitrary regions and uses a shape adaptive embedded zerotree wavelet coding (SA-EZW) to quantize the selected coefficients. Since the shape information is implicitly encoded by the SA-EZW, our decoder can reconstruct the arbitrary region without separate shape coding. This makes the algorithm simple to implement and avoids the problem of contour coding. Our algorithm also provides a sufficient framework to address content-based scalability and improved coding efficiency as described by MPEG I.

关键词： region based content based zerotree coefficients selection wavelet coding

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Robust EZW image coding for noisy channels

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IEEE SIGNAL PROCESSING LETTERS 1997年第8期4卷 227-229页

作者： Man, H Kossentini, F Smith, MJT UNIV BRITISH COLUMBIA DEPT ELECT ENGNVANCOUVERBC V6T 1Z4CANADA

We present a new embedded zerotree wavelet image coding algorithm that is based on the algorithms developed by Shapiro and Said ct al, Our algorithm features a relatively simple coding structure and provides a better framework for balancing between high compression performance and robustness to channel errors, The fundamental approach is to explicitly classify the encoder's output bit sequence into subsequences, which are then protected differently according to their importance and robustness, Experimental results indicate that, for noisy channels, the proposed algorithm is slightly more resilient to channel errors than more complex and sophisticated source-channel coding algorithms, More important is that our algorithm is substantially more robust with respect to varying channel error conditions, This provides much needed reliability in low-bandwidth wireless applications.

关键词： channel error robustness and resilience coding embedded zerotrees joint source-channel wavelet coding

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Low bit-rate subband image coding with matching pursuits

Low bit-rate subband image coding with matching pursuits

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Visual Communications and Image Processing 1998 Conference

作者： Rabiee, HR Safavian, SR Gardos, TR Mirani, AJ Intel Corp Media & Interconnect Technol Lab Hillsboro OR 97124 USA

ISBN: (纸本)0819427497

In this paper, a novel multiresolution algorithm for low bit-rate image compression is presented. High quality low bit-rate image compression is achieved by first decomposing the image into approximation and detail subimages with a shift-orthogonal multiresolution analysis. Then, at the coarsest resolution level, the coefficients of the transformation are encoded by an orthogonal matching pursuit algorithm with a wavelet packet dictionary. Our dictionary consists of convolutional splines of up to order two for the detail and approximation subbands. The intercorrelation between the various resolutions is then exploited by using the same bases from the dictionary to encode the coefficients of the finer resolution bands at the corresponding spatial locations. To further exploit the spatial correlation of the coefficients, the zero trees of wavelets (EZW) algorithm [I] was used to identify the potential zero trees. The coefficients of the presentation are then quantized and arithmetic encoded at each resolution, and packed into a scalable bit stream structure. Our new algorithm is highly bit-rate scalable, and performs better than the segmentation based matching pursuit [2,3] and EZW encoders at lower bit rates, based on subjective image quality and peak signal-to-noise ratio (PSNR).

关键词： image compression scalable coding multiresolution coding subband coding matching pursuit wavelet coding

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A scene adaptive and signal adaptive quantization for subband image and video compression using wavelets

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1997年第2期7卷 343-357页

作者： Luo, JB Chen, DW Parker, KJ Huang, TS UNIV ROCHESTER DEPT ELECT ENGN CTR ELECT IMAGING SYST ROCHESTER NY 14627 USA UNIV ILLINOIS BECKMAN INST URBANA IL 61801 USA UNIV ILLINOIS COORDINATED SCI LAB URBANA IL 61801 USA

Discrete wavelet transform (DWT) provides an advantageous framework of multiresolution space-frequency representation with promising applications in image processing, The challenge as well as the opportunity in wavelet-based compression is to exploit the characteristics of the subband coefficients with respect to both spectral and spatial localities, A common problem with many existing quantization methods is that the inherent image structures are severely distorted with coarse quantization, Observation shows that subband coefficients with the same magnitude generally do not have the same perceptual importance;this depends on whether or not they belong to clustered scene structures, We propose in this paper a novel scene adaptive and signal adaptive quantization scheme capable of exploiting both the spectral and spatial localization properties resulting from wavelet transform, The proposed quantization is implemented as a maximum a posteriori probability (MAP) estimation-based clustering process in which subband coefficients are quantized to their cluster means, subject to local spatial constraints, The intensity distribution of each cluster within a subband is modeled by an optimal Laplacian source to achieve the signal adaptivity, while spatial constraints are enforced by appropriate Gibbs random fields (GRF) to achieve the scene adaptivity, Consequently, with spatially isolated coefficients removed and clustered coefficients retained at the same time, the available bits are allocated to visually important scene structures so that the information loss is least perceptible. Furthermore, the reconstruction noise in the decompressed image can be suppressed using another GRF-based enhancement algorithm, Experimental results have shown the potentials of this quantization scheme for low bit-rate image and video compression.

关键词： adaptive quantization image and video compression Gibbs random field spatial constraints subband coding wavelet coding

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Rate-distortion optimized bit rate control scheme for a wavelet video coder

Rate-distortion optimized bit rate control scheme for a wave...

引用

1997 Conference on Visual Communications and Image Processing

作者： Cheng, PY Li, J Kuo, CCJ Physical Optics Corp. (United States) Univ. of Southern California (United States)

ISBN: (纸本)0819424358

The rate control problem can be greatly simplified by using a wavelet coder, since the desired bit rate for a particular frame can be easily reached by using its embedding property. We convert the rate control problem to a bit allocation problem for each frame, and solve it with two models. Frames are assumed to be independent in the basic model while their dependency is taken into account in the advanced model. Two computationally efficient rate control algorithms are then derived. Extensive experiments are performed to demonstrate the superior performance of the wavelet coder with the proposed rate control schemes over the MPEG standard with test model 5 (TM5).

关键词： rate control video coding wavelet coding

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Embedded wavelet packet image coder with fast rate-distortion optimized decomposition

Embedded wavelet packet image coder with fast rate-distortio...

引用

1997 Conference on Visual Communications and Image Processing

作者： Li, J Kuo, CCJ Cheng, PY Univ. of Southern California (United States) Physical Optics Corp. (United States)

ISBN: (纸本)0819424358

A fast rate-distortion (R-D) optimized wavelet packet (WP) transform is proposed for image compression in this research. By analyzing the R-D performance of the quantizer and the entropy coder, we show that the coding distortion D can be modeled as an exponentially decaying function as the coding rate R increases. With this exponential R-D model, it is proved that the constant R-D slope criterion for optimum bit allocation is equivalent to the constant distortion criterion, which can be easily implemented via thresholding. Based on this analytical result, we develop a fast wavelet packet decomposition scheme which is optimized in the R-D sense by comparing simple parameters associated with each wavelet packet band such as the 1st or 2nd absolute moments. We have performed extensive experiments to demonstrate the performance of an image coder using the proposed R-D optimized wavelet packet transform, and shown that our scheme is highly competitive with all well known state-of-the-art image coders.

关键词： image compression rate-distortion wavelet packets wavelet coding embedded coding

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OPTIMAL wavelet TREE PRUNING FOR IMAGE coding

OPTIMAL WAVELET TREE PRUNING FOR IMAGE CODING

引用

Conference on Digital Video Compression - Algorithms and Technologies 1995

作者： ANG, YH BI, M ONG, SH NATL UNIV SINGAPORE INST SYST SCISINGAPORE 0511SINGAPORE

ISBN: (纸本)0819417661

In this paper, an optimal image coding scheme based on wavelet decomposition and vector quantization is proposed. The selection of wavelet transformed coefficients for encoding is performed using an optimal tree-pruning algorithm. Optimum selection of wavelet coefficients is achieved by minimizing the overall residual quantization error of the pruned tree. The pruning process takes into consideration the image structure and exploits the spatial masking effect of the human visual system. This reduces the overall coding bit rate without scarifying the perceptual quality in the reconstructed image. Vector quantization of the selected wavelet coefficients (pruned-tree) is performed using our proposed multiresolution product codebook. The optimal design of the product codebook is characterized by its minimized and equally distributed quantization distortions of individual sub-codebooks.

关键词： wavelet TREE PRUNING wavelet coding MULTIRESOLUTION CODEBOOK PRODUCT CODEBOOK

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