小波变换 matlab程序

小波变换的图像处理%MATLAB2维小波变换经典程序 % FWT_DB.M; % 此示意程序用DWT实现二维小波变换 % 编程时间2004-4-10，编程人沙威 %%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%% clear; clc; T=256; % 图像维数 SUB_T=T/2; % 子图维数 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % 1.调原始图像矩阵 load wbarb; % 下载图像 f=X; % 原始图像 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % 2.进行二维小波分解 l=wfilters('db10','l'); % db10（消失矩为10)低通分解滤波器冲击响应（长度为20） L=T-length(l); l_zeros=[l,zeros(1,L)]; % 矩阵行数与输入图像一致，为2的整数幂 h=wfilters('db10','h'); % db10（消失矩为10)高通分解滤波器冲击响应（长度为20） h_zeros=[h,zeros(1,L)]; % 矩阵行数与输入图像一致，为2的整数幂 for i=1:T; % 列变换 row(1:SUB_T,i)=dyaddown( ifft( fft(l_zeros).*fft(f(:,i)') ) ).'; % 圆周卷积FFT row(SUB_T+1:T,i)=dyaddown( ifft( fft(h_zeros).*fft(f(:,i)') ) ).'; % 圆周卷积FFT end; for j=1:T; % 行变换 line(j,1:SUB_T)=dyaddown( ifft( fft(l_zeros).*fft(row(j,:)) ) ); % 圆周卷积FFT line(j,SUB_T+1:T)=dyaddown( ifft( fft(h_zeros).*fft(row(j,:)) ) ); % 圆周卷积FFT end; decompose_pic=line; % 分解矩阵 % 图像分为四块 lt_pic=decompose_pic(1:SUB_T,1:SUB_T); % 在矩阵左上方为低频分量--fi(x)*fi(y) rt_pic=decompose_pic(1:SUB_T,SUB_T+1:T); % 矩阵右上为--fi(x)*psi(y) lb_pic=decompose_pic(SUB_T+1:T,1:SUB_T); % 矩阵左下为--psi(x)*fi(y) rb_pic=decompose_pic(SUB_T+1:T,SUB_T+1:T); % 右下方为高频分量--psi(x)*psi(y) %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % 3.分解结果显示 figure(1); colormap(map); subplot(2,1,1); image(f); % 原始图像 title('original pic'); subplot(2,1,2); image(abs(decompose_pic)); % 分解后图像 title('decomposed pic'); figure(2); colormap(map); subplot(2,2,1); image(abs(lt_pic)); % 左上方为低频分量--fi(x)*fi(y) title('\Phi(x)*\Phi(y)'); subplot(2,2,2); image(abs(rt_pic)); % 矩阵右上为--fi(x)*psi(y) title('\Phi(x)*\Psi(y)'); subplot(2,2,3); image(abs(lb_pic)); % 矩阵左下为--psi(x)*fi(y) title('\Psi(x)*\Phi(y)'); subplot(2,2,4); image(abs(rb_pic)); % 右下方为高频分量--psi(x)*psi(y) title('\Psi(x)*\Psi(y)'); %%%%%%%