We address the problem of resilient imagecoding over error-prone networks where packet losses occur. Recent literature highlights the multiple description coding (MDC) as a promising approach to solve this problem. I...
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We address the problem of resilient imagecoding over error-prone networks where packet losses occur. Recent literature highlights the multiple description coding (MDC) as a promising approach to solve this problem. In this paper, we introduce a novel wavelet-based multiple description image coder, referred to as the feature-oriented MDC (FO-MDC). The proposed multiple description (MD) coder exploits the statistics of the wavelet coefficients and identifies the subsets of samples that are sensitive to packet loss. A joint optimization between tree-pruning and quantizer selection in the rate-distortion sense is used in order to allocate more bits to these sensitive coefficients. When compared with the state-of-the-art MD scalar quantization coder, the proposed FO-MDC yields a more efficient central-side distortion tradeoff control mechanism. Furthermore, it proves to be more robust for image transmission even with high packet loss ratios, which makes it suitable for protecting multimedia streams over packet-erasure channels.
This work defines an entropy-based measure aimed to establish the compression limits of wavelet-based image coding. This measure serves to appraise the efficiency of current codecs, determining whether there is margin...
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ISBN:
(纸本)9781479934188
This work defines an entropy-based measure aimed to establish the compression limits of wavelet-based image coding. This measure serves to appraise the efficiency of current codecs, determining whether there is margin for their improvement or not. Also, it may help to design new compression schemes that target a particular type of images and/or compression rates, and may assess the decorrelation efficiency of different transform strategies.
The curved wavelet transform performs 1-D filtering along curves and exploits orientation features of edges and lines in an image to improve the compactness of the wavelet transform. This paper investigates the issue ...
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ISBN:
(纸本)0819456586
The curved wavelet transform performs 1-D filtering along curves and exploits orientation features of edges and lines in an image to improve the compactness of the wavelet transform. This paper investigates the issue of efficient data organization and representation of the curved wavelet coefficients. We present an adaptive zero-tree structure that exploits the cross-subband similarity of the curved wavelet transform. The child positions in the adaptive zero-tree structure are not restricted to a square of 2x2 pixels and they vary with the curves along which the WT is performed. Five child patterns have been determined according to different combination of curve orientations. A new image coder, using the curved wavelet transform, is then developed based on this adaptive zero-tree structure and the set partitioning technique. Experimental results using synthetic and natural images show the effectiveness of the proposed adaptive zero-tree structure for encoding of the curved wavelet coefficients. The coding gain of the proposed coder can be as higher as 1.2dB in terms of PSNR compared to the SPIHT coder.
Modern image and video compression standards employ computationally intensive algorithms that provide advanced features to the coding system. Current standards often need to be implemented in hardware or using expensi...
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Modern image and video compression standards employ computationally intensive algorithms that provide advanced features to the coding system. Current standards often need to be implemented in hardware or using expensive solutions to meet the real-time requirements of some environments. Contrarily to this trend, this paper proposes an end-to-end codec architecture running on inexpensive Graphics Processing Units (GPUs) that is based on, though not compatible with, the JPEG2000 international standard for image and video compression. When executed in a commodity Nvidia GPU, it achieves real time processing of 12K video. The proposed S/W architecture utilizes four CUDA kernels that minimize memory transfers, use registers instead of shared memory, and employ a double-buffer strategy to optimize the streaming of data. The analysis of throughput indicates that the proposed codec yields results at least superior on average to those achieved with JPEG2000 implementations devised for CPUs, and approximately superior to those achieved with hardwired solutions of the HEVC/H.265 video compression standard.
Far wavelet-based image coding, it is important to efficiently code the significance map for each bit plane. The proposed algorithm provides an effective method for coding the significance map by using block-based zer...
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Far wavelet-based image coding, it is important to efficiently code the significance map for each bit plane. The proposed algorithm provides an effective method for coding the significance map by using block-based zerotree and quadtree decomposition, and demonstrates good R-D performance especially at low bit rates and for images with rich texture.
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