This paper discusses the most recent trends in the reversible intraframe compression of grayscale images. With reference to a spatial DPCM scheme,prediction, either linar or nonlinear, may be accomplished in a space-v...
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ISBN:
(纸本)0819433004
This paper discusses the most recent trends in the reversible intraframe compression of grayscale images. With reference to a spatial DPCM scheme,prediction, either linar or nonlinear, may be accomplished in a space-varying fashion following two main strategies: adaptive, i.e., with predictors recalculated at each pixel position, and classified, in which image blocks, or pixels are preliminarily labeled into a number of statistical classes, for which optimum MMSE predictors are calculated. A trade-off between the above two strategies is proposed. It relies on a classified linear-regression prediction obtained through fuzzy techniques, followed by context-based modeling of the outcome prediction errors, to enhance entropy coding. The present scheme is a reworking of a fuzzy encoder previously presented by the authors. Now, predictors, instead of pixel intensity patterns, are fuzzy-clustered to find out, optimized MMSE prediction classes, and a novel membership function measuring the fitness of prediction is adopted. A thorough performances comparison with the most advanced methods in the literature highlights advantages, and drawbacks as well, of the fuzzy approach.
This paper presents a new truncated Baker transformation with a finite precision and extends it to an efficient imageencryption scheme. The truncated Baker transformation uses the quantization error as a secret key, ...
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ISBN:
(纸本)0819433004
This paper presents a new truncated Baker transformation with a finite precision and extends it to an efficient imageencryption scheme. The truncated Baker transformation uses the quantization error as a secret key, which is always produced by contraction mechanism in the mapping process. The original dynamics by Baker transformation is globally preserved but a random local rotation operator is incorporated between two neighbor elements in the mapping domain in order to keep the same precision. Such perturbations are local and small in each mapping, however, as the mapping process goes on they will gradually accumulate and affect the whole dynamics. Consequently, generated binary sequences (the dynamics of elements) have statistically good features on ergodicity, mixing and chaotic properties. The extended imageencryption scheme efficiently shuffle the input gray level image making difficult for a third party to decode the ciphered data to the original image without knowing the proper secret key.
One result of the recent advances in different components of imaging systems technology is that, these systems have become more resolution-limited and less noise-limited. The most useful tool utilized in characterizat...
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ISBN:
(纸本)0819433004
One result of the recent advances in different components of imaging systems technology is that, these systems have become more resolution-limited and less noise-limited. The most useful tool utilized in characterization of resolution-limited systems is the Modulation Transfer Function (MTF). The goal of this work is to use the MTF as an image quality measure of imagecompression implemented by the JPEG (Joint Photographic Expert Group) algorithm and transmitted MPEG (Motion Picture Expert Group) compressed video stream through a lossy packet network. Although we realize that the MTF is not an ideal parameter with which to measure image quality after compression and transmission due to the non-linearity shift invariant process, we examine the conditions under which it can be used as an approximated criterion for image quality. The advantage in using the MTF of the compression algorithm is that it can be easily combined with the overall MTF of the imaging system.
In the paper we present comparison of three advanced techniques for video compression. Among them 3D Embedded Zerotree Wavelet (EZW) coding. recently suggested Optimal imagecoding.using Karhunen-Loeve (KL) transform ...
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In the paper we present comparison of three advanced techniques for video compression. Among them 3D Embedded Zerotree Wavelet (EZW) coding. recently suggested Optimal imagecoding.using Karhunen-Loeve (KL) transform (OICKL) and new algorithm of video compression based on 3D EZW coding.scheme but with using KL transform for frames decorrelation (3D-EZWKL). It is shown that OICKL technique provides the best performance and usage of KL transform with 3D-EZW coding.scheme gives better results than just usage of 3D-EZW algorithm.
A high-compressionimage transformation method called enhanced blurring, local averaging, and thresholding (EBLAST), is presented that facilitates image transmission along low-bandwidth channels and exhibits low mean-...
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A high-compressionimage transformation method called enhanced blurring, local averaging, and thresholding (EBLAST), is presented that facilitates image transmission along low-bandwidth channels and exhibits low mean-squared error with spatially uniform construction error. Analyses of EBLAST's formulation and implementation emphasize assessment of EBLAST's performance on a suite of innovative image quality measures as well as more traditional metrics such as computational cost, ease of parallelization, and scalability.
The techniques for mapping blockwise compression transforms to reconfigurable architectures are presented. The computational precision is varied among different operations within the given transform. The mapping of ar...
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The techniques for mapping blockwise compression transforms to reconfigurable architectures are presented. The computational precision is varied among different operations within the given transform. The mapping of arithmetic operations in various compression transforms to lookup tables (LUT) that can be directly implemented in memory based devices is analyzed. The feasibility of LUT-based transcendental operations, which would be the key to fast implementations of the discrete cosine transform that comprises the core of the Joint Picture Expert Group (JPEG) algorithm is discussed.
Vector quantization (VQ), a well-established imagecompression technique, is attractive due to its mathematically simple compression formulation and efficient decompression implementation. Unfortunately, VQ typically ...
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Vector quantization (VQ), a well-established imagecompression technique, is attractive due to its mathematically simple compression formulation and efficient decompression implementation. Unfortunately, VQ typically suffers from high cost of codebook computation, as well as relatively high codebook search overhead during compression. Such costs can be prohibitive when VQ is employed in real-time surveillance applications, especially with large-format images and moderate to high compression ratios. In response to this situation, Frontier Technology, Inc. has developed an efficient codebook search technique called Tabular Nearest Neighbor Encoding.(TNE). This approach significantly reduces the codebook search cost for VQ- and VQ-like compression algorithms, and can increase pattern-matching accuracy and efficiency in template-based automated target recognition (ATR) applications. In particular, TNE's VQ-like codebook can represent a database of target patterns for ATR purposes, which tends to yield an increase in pattern matching efficiency due to the processing of fewer (encoded) data. In this series of two papers, a high-level overview of the TNE algorithm is presented. The performance of TNE is analyzed using training images having different size, statistical properties, and noise level than the source image. TNE is compared with several published algorithms such as visual pattern imagecoding.(VPIC), JPEG, and EBLAST. The latter is a relatively new, high-compressionimage transform that has compression ratio CR200:1 that can be consistently achieved with low MSE. Analysis focuses on the ability of TNE to provide low to moderate compression ratios at high computational efficiency on small- to large-format text and surveillance images.
This paper discusses the most recent trends in the reversible intraframe compression of grayscale images. With reference to a spatial DPCM scheme, prediction, either linar or nonlinear, may be accomplished in a space-...
详细信息
ISBN:
(纸本)0819433004
This paper discusses the most recent trends in the reversible intraframe compression of grayscale images. With reference to a spatial DPCM scheme, prediction, either linar or nonlinear, may be accomplished in a space-varying fashion following two main strategies: adaptive, i.e., with predictors recalculated at each pixel position, and classified, in which image blocks, or pixels are preliminarily labeled into a number of statistical classes, for which optimum MMSE predictors are calculated. A trade-off between the above two strategies is proposed. It relies on a classified linear-regression prediction obtained through fuzzy techniques, followed by context-based modeling of the outcome prediction errors, to enhance entropy coding. The present scheme is a reworking of a fuzzy encoder previously presented by the authors. Now, predictors, instead of pixel intensity patterns, are fuzzy-clustered to find out optimized MMSE prediction classes, and a novel membership function measuring the fitness of prediction is adopted. A thorough performances comparison with the most advanced methods in the literature highlights advantages, and drawbacks as well, of the fuzzy approach.
This Volume 3456 of the conference proceedings contains 20 papers. Topics discussed include mathematics of data/image coding. compression and encryption, digital watermarking and encryption, imagecompression, error d...
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This Volume 3456 of the conference proceedings contains 20 papers. Topics discussed include mathematics of data/image coding. compression and encryption, digital watermarking and encryption, imagecompression, error detection, modeling and management.
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