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Ratio-modified block truncation coding algorithms for reduced bitrates

IMAGING SCIENCE JOURNAL 2011年第1期59卷 25-31页

作者： Natarajan, S. Rao, Y. V. Ramana Bannari Amman Inst Technol Dept Elect & Commun Engn Sathyamangalam 638401 Tamilnadu India Anna Univ Coll Engn Dept Elect & Commun Engn Madras 600025 Tamil Nadu India

Block truncation coding (BTC) technique is a simple and fast image compression algorithm since complicated transforms are not used. The principle used in BTC algorithm is to use two-level quantiser that adapts to local properties of the image while preserving the first- or first- and second-order statistical moments. The parameters transmitter or stored in the BTC algorithm are statistical moments and bitplane yielding good quality images at a bitrate of 2 bits per pixel (bpp). In this paper, two algorithms for modified BTC (MBTC) are proposed for reducing the bitrate below 2 bpp. The principal used in the proposed algorithms is to use the ratio of moments which is a smaller value when compared to absolute moments. The ratio values are then entropy coded. The bitplane is also coded to remove the correlation among the bits. The proposed algorithms are compared with MBTC and the algorithms obtained by combining JPEG standard with MBTC in terms of bitrate, peak signal-to-noise ratio (PSNR) and subjective quality. It is found that the reconstructed images obtained using the proposed algorithms yield better results.

关键词： image coding block truncation coding JPEG arithmetic coding bitplane coding

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A coding SCHEME FOR M-OUT-OF-N CODES

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IEEE TRANSACTIONS ON COMMUNICATIONS 1990年第8期38卷 1156-1163页

作者： RAMABADRAN, TV Department of Electrical and Computer Engineering Iowa State University Ames IA USA

A new scheme for the construction of m-out-of* codes based on the arithmetic coding technique is described. For appropriate values of n , k , and m, the scheme can be used to construct an (n,k) Mock code in which all the codewords are of weight m. Such codes are useful, for example, in providing perfect error detection capabil- ity in asymmetric channels such as optical communication links and laser disks. The encoding and decoding algorithms of the scheme per- form simple arithmetic operations recursively, thereby facilitating the construction of codes with relativelylong Mock sizes. The scheme also allows the construction of optimal or naarly optimal m-out-of* codes for a wide range of block sizes limited only by the arithmetic precision used.

关键词： .codewords arithmetic coding coding Scheme information bits error detection block sizes out-of code number of check ropt rapt

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Patch-Based Conditional Context coding of Stereo Disparity Images

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IEEE SIGNAL PROCESSING LETTERS 2014年第10期21卷 1220-1224页

作者： Tabus, Ioan Tampere Univ Technol Dept Signal Proc FIN-33101 Tampere Finland

This letter proposes a method for lossless coding the left disparity image, L, from a stereo disparity image pair (L, R), conditional on the right disparity image, R, by keeping track of the transformation of the constant patches from R to L. The disparities in R are used for predicting the disparities in L, and the locations of the pixels where the prediction is erroneous are encoded in a first stage, conditional on the patch-labels of R image, allowing the decoder to already reconstruct with certainty some elements of the L image, e.g., the disparity values at certain pixels and parts of the contours of left image patches. Second, the contours of the patches in L image that are still unknown after first stage are conditionally encoded using a mixed conditioning context: the usual causal current context from the contours of L and a noncausal context extracted from the contours in the correctly estimated part of L obtained in the first stage. The depth values in the patches of L image are finally encoded, if they are not already known from the prediction stage. The new algorithm, dubbed conditional crack-edge region value (C-CERV), is shown to perform significantly better than the non-conditional coding method CERV and than another existing conditional coding method, over the Middlebury corpus. C-CERV is shown to reach lossless compression ratios of 100-250 times for those images that have a high precision of the disparity map.

关键词： arithmetic coding context tree coding inter-coding lossless disparity image compression

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Adaptive CU splitting and pruning method for HEVC intra coding

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ELECTRONICS LETTERS 2014年第10期50卷 748-U131页

作者： Kim, Gaewon Yim, Changhoon Konkuk Univ Dept Internet & Multimedia Engn Seoul South Korea

coding unit (CU) splitting and pruning for complexity reduction in high-efficiency video coding (HEVC) intra coding is dealt with. Adaptive determination of the threshold values for splitting and pruning in each CU is proposed based on the depth level information of neighbour CUs, whose values are determined from a fixed parameter in the previous method. Simple preconditions for splitting and pruning are also proposed to improve coding efficiency. Simulation results show that the proposed method gives significant improvement of computational complexity with much smaller reduction of coding efficiency compared with the previous method.

关键词： VIDEO coding (Computer science) arithmetic coding SPLITTING extrapolation method SIMULATION methods & models COMPUTATIONAL complexity

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BINARY-UNCODED IMAGE AND VIDEO COMPRESSION USING SPIHT-ZTR coding

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INTERNATIONAL JOURNAL OF IMAGE AND GRAPHICS 2011年第3期11卷 415-437页

作者： Chia, Wai Chong Chew, Li Wern Ang, Li-Minn Seng, Kah Phooi Univ Nottingham Sch Elect & Elect Engn Selangor 43500 Malaysia

When the embedded zerotree wavelet (EZW) algorithm was first introduced by Shapiro, four types of symbols (zerotree (ZTR), isolated zero (IZ), positive (POS), and negative (NEG)) were used to represent the tree structure. An improved version of EZW, the set partitioning in hierarchical trees (SPIHT) algorithm was later proposed by Said and Pearlman. SPIHT removed the ZTR symbol, while keeping the other three symbols in a slightly different form. In the SPIHT algorithm, the coding of the parent node is isolated from the coding of its descendants in the tree structure. Therefore, it is no longer possible to encode the parent and its descendants with a single symbol. When both the parent and its descendants are insignificant (forming a degree-0 zerotree (ZTR)), it cannot be represented using a ZTR symbol. From our observation, the number of degree-0 ZTRs can occur very frequently not only in natural and synthesis images, but also in video sequences. Hence, the ZTR symbol is reintroduced into SPIHT in our proposed SPIHT-ZTR algorithm. In order to achieve this, the order of sending the output bits was modified to accommodate the use of ZTR symbol. Moreover, the significant offspring were also encoded using a slightly different method to further enhance the performance. The SPIHT-ZTR algorithm was evaluated on images and video sequences. From the simulation results, the performance of binary-uncoded SPIHT-ZTR is higher than binary-uncoded SPIHT and close to SPIHT with adaptive arithmetic coding.

关键词： SPIHT EZW image compression video compression arithmetic coding

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Context modeling for near-lossless image coding

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IEEE SIGNAL PROCESSING LETTERS 2002年第3期9卷 77-80页

作者： Aiazzi, B Alparone, L Baronti, S CNR IROE Nello Carrara Res Inst Electromagnet Waves I-50127 Florence Italy Univ Florence Dept Elect & Telecommun I-50139 Florence Italy

This letter describes a context-based entropy coding suitable for any causal spatial differential pulse code modulation (DPCM) scheme performing lossless or near-lossless image coding. The proposed method is based on partitioning of prediction errors into homogeneous classes before arithmetic coding. A context function is measured on prediction errors lying within a two-dimensional (2-D) causal neighborhood, comprising the prediction support of the current pixel, as the root mean square (RMS) of residuals weighted by the reciprocal of their Euclidean distances. Its effectiveness is demonstrated in comparative experiments concerning both lossless and near-lossless coding. The proposed context coding/decoding is strictly real-time.

关键词： arithmetic coding DPCM entropy coding near-lossless coding statistical context modeling

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coding for a binary independent piecewise-identically-distributed source

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IEEE TRANSACTIONS ON INFORMATION THEORY 1996年第6期42卷 2210-2217页

作者： Willems, FMJ Dept. of Electr. Eng. Eindhoven Univ. of Technol. Netherlands

Two weighting procedures are presented for compaction of output sequences generated by binary independent sources whose unknown parameter may occasionally change, The resulting codes need no knowledge of the sequence length T, i.e., they are strongly sequential, and also the number of parameter changes is unrestricted, The additional-transition redundancy of the first method was shown to achieve the Merhav lower bound, i.e., log T bits per transition, For the second method we could prove that additional-transition redundancy is not more than 3/2 log T bits per transition, which is more than the Merhav bound;however, the storage and computational complexity of this method are also more interesting than those of the first method, Simulations show that the difference in redundancy performance between the two methods is negligible.

关键词： universal noiseless source coding independent piecewise-identically-distributed source nonstationary source transition pattern weighting arithmetic coding redundancy bounds

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Low-Complexity Lossless Image coding

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AUTOMATIC CONTROL AND COMPUTER SCIENCES 2014年第5期48卷 303-311页

作者： Bocharova, I. E. Porov, A. V. Bondarev, T. S. Finkelshteyn, O. V. Natl Res Univ Informat Technol Mech & Opt Kronverksky Prosp 49 St Petersburg 197101 Russia

A new lossless image coding method competitive with the best known image coding techniques in terms of efficiency and complexity is suggested. It is based on adaptive color space transform, adaptive context coding, and improved prediction of pixel values of image color components. Examples of application of the new algorithm to a set of standard images are given and comparison with known algorithms is performed.

关键词： lossless compression linear prediction image coding context coding color space transform arithmetic coding

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Block-based wavelet transform coding of mammograms with region adaptive quantization

Block-based wavelet transform coding of mammograms with regi...

引用

Conference on Image Display - Medical Imaging 1998

作者： Moon, NS Song, JS Kwon, M Kim, JH Lee, CW Seoul Natl Univ Sch Elect Engn Inst New Media & Commun Seoul 151 South Korea

ISBN: (纸本)0819427802

To acheive both high compression ratio and information preserving, it is an efficiet way to combine segmentation and lossy compression scheme. Microcalcification in mammogram is one of the most significant sign of early stage of breast cancer. Therefore in coding, detection and segmentation of microcalcification enable us to preserve it well by allocating more bits to it than to other regions. Segmentation of microcalcification is performed both in spatial domain and in wavelet transform domain. Peak error controllable quantization step, which is off-line designed, is suitable for medical image compression. For region-adaptive quantization, block-based wavelet transform coding is adopted and different peak-error-constrained quantizers are applied to blocks according to the segmentation result. In view of perservation of microcalcification, the proposed coding scheme shows better performance than JPEG.

关键词： block-based wavelet transform coding peak error controllable quantization arithmetic coding

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The Novel Improving Algorithms on DRA Audio Entropy coding

The Novel Improving Algorithms on DRA Audio Entropy Coding

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10th IEEE International Conference on Signal Processing, Communications and Computing (IEEE ICSPCC)

作者： Yan, Jianxin Wang, Lei Natl Engn Lab Digital Audio Coding Technol Guangzhou Peoples R China

ISBN: (纸本)9781728172019

DRA (Digital Rise Audio) is referred to as specification for multi-channel digital audio coding technology which was issued as a Chinese national standard in 2008. There novel algorithms which are the differential Huffman, context-based Huffman and context-based arithmetic entropy coding, respectively, are presented to improve the compression efficiency of DRA entropy coding with 3%, 11.11% and 13.52% at the expense of the different implementing complexities and the intra-frame and/or inter-frame error propagation in live transmission.

关键词： entropy coding Huffman coding arithmetic coding audio compression

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