bayesthresh2.m

基于小波变换的多种去噪方法在matlab上的实现

function [x,thresh]=BayesThresh2(y)
%
%%%%%%%%%%%%%%%It's my own function!!!!!
%
%y --  2-d wavelet coefficient

sigma=1;%噪声方差已归一化为1
n=length(y);
sigmaY2=sum(sum(y.^2))/n/n;%带噪声信号方差
temp=sigmaY2-sigma^2;
if temp>0
    sigma_xNoiseless=sqrt(temp);%不带噪声信号方差估计
    thresh=sigma^2/sigma_xNoiseless;
else
    thresh=max(max(abs(y)));
end;

x      = SoftThresh(y,thresh);