第19卷第1期 2011年1月
文章编号
1004-924X(2011)01-0175-08
光学精密工程
Optics and Precision Engineering
Vol.19No.1
Jan.2011
基于游程和扩展指数哥伦布编码的任意形状
感兴趣区域图像编码徐勇12，徐智勇1，张启衡
（1.中国科学院光电技术研究所，四川成都610209；2.中国科学院研究生院，北京100039）
摘要：给出~种上下文自适应的游程编码和扩展指数哥伦布编码。利用游程编码算法对图像小波系数及ROI掩模进行上下文自适应建模并输出三元组样本；然后扩展普通的指数哥伦布编码，使其可以编码由游程编码建模输出的三元组样本，在对小波系数编码的同时可以携带感兴趣区域掩模标记信息，由此得到一种可以区别感兴趣区城和背景区域的高效编码算法，并以此算法为基础提出一种感兴趣区域编码的编解码椎架，该框架包括5/3小波变换、小波域捷模标记生成、不均匀最佳量化、游程编码和扩展的指数再伦布编码。该算法的游程建模过程简单，摘编码算法可用闭合公式表达，具有较高的可实现性。实验结果表明，提出的算法支持多个任意形状的感兴趣区域，感兴趣区域相对于背景区域的编码
优先级可调，并且可以获得高于基于BbB-shift的SPIHT算法的压缩性能。关键调：围像编弱；感兴趣区城编码；自适应游程编弱：指数导伦布编码
中图分类号：TN919.81
文献标识码：A
doi:10.3788/OPE,20111901.0175
ArbitraryshapedROIimagecodingusingRun-lengthcoding
andgeneralizedExp-Golombcoding XU Yong'-2,XU Zhi-yong',ZHANG Qi-heng
(l.InstituteofOptics andElectronics,ChineseAcademyof Sciences,Chengdu6lo2o9,China;
2.GraduateUniversity of ChineseAcademyof Sciences,Beijing100039,China)
Abstract: A context adaptive tri-element Run length coding algorithm and an Exp-Golomb coding al-ogorithm were introduced,The Run-length coding was used to model the image wavelet coefficients and the Region of Interest(ROI) mask and to yield tri-element codes. Then, the conventional Exp Golomb coding was expanded to encode tri-element codes from Run-length coding and to carry the ROI mask together.Based on the two algorithms above,a high efficient algorithm to distinguish the ROl and background was obtained and a ROI codec framework was proposed. The framework includes 5/3 wavelet transform, wavelet domain mask generation, non-uniform optimal quantization, context adap-tive tri-element Run-length coding and generalized Exp-Golomb coding. The tri-element Run-length coding in this algorithm is brief, and the expanded Exp-Golomb coding can be expressed by a closed formula. Experimental results show that the algorithm supports multiple arbitrary-shaped ROI and the adjustability of the ROI is prior to that of the background region, Furthermore, it achieves higher
收稿日期：2010-04-06；修订日期：2010-06-30
基金项目：国防创新基金资助项目（No.CXJJ-259）