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喷泉码中不定帧长LT码及其生成矩阵的优化 被引量:2
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作者 赵旦峰 钱晋希 吴宇平 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2011年第7期953-957,共5页
针对喷泉码中LT(Luby transform)码编码效率不高、需传送的数据量大、时延长且译码概率低等弊端,将数学极限分析方法引入LT码的度数分布中,提出了一种不定帧长LT码方案,并且在不定帧长LT码的生成矩阵中引入改进的熵编码压缩算法,得到了... 针对喷泉码中LT(Luby transform)码编码效率不高、需传送的数据量大、时延长且译码概率低等弊端,将数学极限分析方法引入LT码的度数分布中,提出了一种不定帧长LT码方案,并且在不定帧长LT码的生成矩阵中引入改进的熵编码压缩算法,得到了以熵编码为基础的不定帧长LT码系统模型.其核心思想是先将原始数据进行适当的帧长设计,通过不定帧长的方法对原始数据进行拆分编译码,以满足不同的性能要求,然后对生成矩阵按列进行熵编码优化,使得在不破坏喷泉码特性的前提下大大减少所需传送的数据量.理论分析和仿真结果表明:与已提出的LT码相比,该系统能够有效地提高其编码效率和译码概率,降低LT码的编译码数据量和运算量. 展开更多
关键词 喷泉码 LT码 不定帧长 极限分析方法 熵编码压缩
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A LOSSLESS COMPRESSION ALGORITHM OF REMOTE SENSING IMAGE FOR SPACE APPLICATIONS 被引量:3
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作者 Sui Yuping Yang Chengyu +3 位作者 Liu Yanjun Wang Jun Wei Zhonghui He Xin 《Journal of Electronics(China)》 2008年第5期647-651,共5页
A simple and adaptive lossless compression algorithm is proposed for remote sensing image compression, which includes integer wavelet transform and the Rice entropy coder. By analyzing the probability distribution of ... A simple and adaptive lossless compression algorithm is proposed for remote sensing image compression, which includes integer wavelet transform and the Rice entropy coder. By analyzing the probability distribution of integer wavelet transform coefficients and the characteristics of Rice entropy coder, the divide and rule method is used for high-frequency sub-bands and low-frequency one. High-frequency sub-bands are coded by the Rice entropy coder, and low-frequency coefficients are predicted before coding. The role of predictor is to map the low-frequency coefficients into symbols suitable for the entropy coding. Experimental results show that the average Comprcssion Ratio (CR) of our approach is about two, which is close to that of JPEG 2000. The algorithm is simple and easy to be implemented in hardware. Moreover, it has the merits of adaptability, and independent data packet. So the algorithm can adapt to space lossless compression applications. 展开更多
关键词 Remote sensing image Lossless compression Rice entropy coder Integer Discrete Wavelet Transform (DWT)
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