Summary form only given. An algorithm for lossless compression of tables with numeric attributes based on row ordering is proposed. Extensive experiments were performed on randomly generated and scientific multidimens...
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Summary form only given. An algorithm for lossless compression of tables with numeric attributes based on row ordering is proposed. Extensive experiments were performed on randomly generated and scientific multidimensional tables with numerical attributes. The results showed that ordering is useful for compression of moderately large to large tables with intrinsic dimensionality below 20 and with attributes represented with low to moderate precision. The benefits of the iterative ordering procedure are the largest on data tables with correlated attributes and heterogeneous attribute types
In this paper, a novel adaptive variable-length quantizer design is proposed and its application to predictive image coding is presented. The new quantiser makes advantage of the fact that more than 80% of the predict...
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ISBN:
(纸本)1424406730;1424406749
In this paper, a novel adaptive variable-length quantizer design is proposed and its application to predictive image coding is presented. The new quantiser makes advantage of the fact that more than 80% of the prediction error data usually reside near the origin and hence can be coded with small number of bits. The remaining 20% of the prediction error data can be coded with larger number of bits which results in smaller file size and enhanced quality of the reconstructed image. The simulation results showed improvements in the peak signal to noise ratio at the expense of increased computational complexity. The improvements in the quality of the compressed images overweight the computational complexity of the model
An adaptive palette reordering method is proposed in this paper to reshape the statistical properties of the color index map of a color-indexed image with a dynamic palette. Unlike other reordering methods, the propos...
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An adaptive palette reordering method is proposed in this paper to reshape the statistical properties of the color index map of a color-indexed image with a dynamic palette. Unlike other reordering methods, the proposed method extracts information from both the color index map and the palette to achieve the objective. The compression performance of JPEG-LS can be significantly improved when the proposed method is used
We investigate the problem of scanning and prediction ("scandiction", for short) of multidimensional data arrays. This problem arises in several aspects of image and video processing, such as predictive codi...
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We investigate the problem of scanning and prediction ("scandiction", for short) of multidimensional data arrays. This problem arises in several aspects of image and video processing, such as predictive coding, where an image is compressed by coding the prediction error sequence resulting from scandicting it. Specifically, given a strongly mixing random field, we show that there exists a scandiction scheme which is independent of the field's distribution, yet almost surely asymptotically achieves the same performance as if this distribution was known. We then discuss the scenario where the Peano-Hilbert scanning order is used, accompanied by an optimal predictor, and derive a bound on the excess loss compared to optimal finite state scandiction, which is valid for any individual image and any bounded loss function.
In current video compression systems the encoder performs computationally demanding predictive coding to exploit temporal correlation between successive frames. In this paper we present a video coder based on the prin...
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In current video compression systems the encoder performs computationally demanding predictive coding to exploit temporal correlation between successive frames. In this paper we present a video coder based on the principles of distributed source coding. Each frame is partitioned into blocks which are then transformed into the DCT domain. After introducing the concept of syndrome-based coding in a continuous domain, we simply use continuous-valued syndromes to represent the DCT coefficients that are expected to be highly correlated with side information created at the decoder. The proposed video coder offers an efficient, low-complexity, error-resilient encoding solution which reuses most of the building blocks of standard DCT-based intra-frame video coding.
In this paper, we propose novel schemes to enhance the error robustness of multi-hypothesis motion-compensate predictive (MHMCP) coder without sacrificing the coding efficiency significantly. The proposed method utili...
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In this paper, we propose novel schemes to enhance the error robustness of multi-hypothesis motion-compensate predictive (MHMCP) coder without sacrificing the coding efficiency significantly. The proposed method utilizes the concept of reference picture interleaving and data partitioning to make the MHMCP-coded video more resilient to channel errors, especially for burst channel error. Besides, we also propose a scheme of integrating adaptive intrarefresh into the proposed MHMCP coder to further improve the error recovery speed. Extensive simulation results show that the proposed methods can effectively and quickly mitigate the error propagation and the penalty on coding efficiency for clean channels due to the inserted error resilience features is rather minor.
This paper proposes a method of lossless image coding by the aid of lossy image coding. It aims at an improvement in the compression efficiency. We apply a kind of embedded coding to large coefficients in magnitude in...
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This paper proposes a method of lossless image coding by the aid of lossy image coding. It aims at an improvement in the compression efficiency. We apply a kind of embedded coding to large coefficients in magnitude in a wavelet transform domain. The other wavelet coefficients are encoded by a context-based entropy coding. The result slightly outperforms the compression efficiency in JPEG-LS.
Nearly all block-based transform schemes for image and video coding developed so far choose the 2-D discrete cosine transform (DCT) of a square block shape. With almost no exception, this conventional DCT is implement...
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Nearly all block-based transform schemes for image and video coding developed so far choose the 2-D discrete cosine transform (DCT) of a square block shape. With almost no exception, this conventional DCT is implemented separately through two 1-D transforms, one along the vertical direction and another along the horizontal direction. In this paper, we develop a new block-based DCT framework in which the first transform may follow a direction other than the vertical or horizontal one, while the second transform is arranged to be a horizontal one. Compared to the conventional DCT, the resulting directional DCT framework is able to provide a better coding performance for image blocks that contain directional edges-a popular scenario in many image signals. By choosing the best from all directional DCT's (including the conventional DCT as a special case) for each image block, we will demonstrate that the rate-distortion coding performance can be improved remarkably
Information theoretic proof exists to support that independent encoding of distributed sources with a joint decoder by exploiting the correlation among the sources can be as efficient as encoding them jointly. This pa...
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Information theoretic proof exists to support that independent encoding of distributed sources with a joint decoder by exploiting the correlation among the sources can be as efficient as encoding them jointly. This paper successfully attempts to apply this concept for lossless video coding using lattices to divide the multidimensional integer pixel intensity hyperspace of a block of pixels into a finite number of cosets and encoding each block with its coset index. This radical departure from conventional predictive coding techniques not only offers very low computational complexity by avoiding expensive learning of predictor coefficients but also avoids any coding loss due to rounding of real-valued predictions. On standard test video sequences, this scheme achieved compression within as low as 4.6% of the latest scheme with optimal learning of predictor coefficients. The former, however, outperformed the latter as soon as it started updating the optimal predictor coefficients less frequently to reduce the computational complexity.
To reduce the computation complexity of discrete cosine transform (DCT) and quantization in H.264 video coding, a highly effective algorithm to detect all-zero DCT coefficient blocks (AZB) before DCT is proposed, afte...
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To reduce the computation complexity of discrete cosine transform (DCT) and quantization in H.264 video coding, a highly effective algorithm to detect all-zero DCT coefficient blocks (AZB) before DCT is proposed, after analyzing the distribution model of DCT coefficients and the properties of the integer DCT and quantization. Experimental results show that the detection ratio of the proposed algorithm achieves up to 98% and up to 47% higher than that of the existing methodologies.
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