数字图像自相关函数的优化逼近模型  

Optimal approximation model of autocorrelation function of digital image

作　　者：成孝刚[1] 陈启美[1] 程浩[2] 刘国庆[2] 安明伟[1] 

机构地区：[1]南京大学电子科学与工程学院,江苏南京210093 [2]南京工业大学理学院,江苏南京210009

出　　处：《通信学报》2011年第10期185-190,共6页Journal on Communications

基　　金：国家科技重大专项基金资助项目(2012ZX03005012;2009ZX03003-007;2011ZX03005-004-03)~~

摘　　要：将复杂的非平稳随机信号划为分段平稳随机信号进行处理,以信号自相关函数反映信号特征。而自相关函数是数字图像频谱分析的基础,可作为图像清晰度评价函数,并有助于寻找有效的信号正交基。为精确有效地表示分段平稳随机信号,在分析ARMA模型、分段平稳随机过程和Markov过程的基础上,建立多参数的自相关函数估计模型,其提高了逼近效果,可适应变化复杂的非平稳信号。计算机仿真表明,该模型逼近误差显著下降。Non-stationary stochastic signal was divided into piecewise stationary stochastic signal,and reflecting the sig-nal’s characteristics by autocorrelation function of the piecewise stationary stochastic signal.Generally,the autocorrela-tion function was the base of selecting signal base for signal representation.For expressing non-stationary stochastic sig-nal in a precise and effective way,based on the analysis of the natural characteristics of ARMA model and Markov proc-ess,a kind of multi-parameter estimation model of autocorrelation function for piecewise stationary stochastic process was proposed.The computational complexity was reduced,and the approximation effect was improved.Furthermore,the multi-parameter estimation model could also be adapted to the complex non-stationary stochastic signal,The computer simulation demonstrates that the approximation error was decreased significantly.

关 键 词：随机过程 分段平稳 非线性逼近 自相关 

分 类 号：TN911.23[电子电信—通信与信息系统]