小波变换用于图像增强、去噪

低频体现轮廓，高频体现细节

clc,clear all,close all;
I=imread('C:\Users\Jv\Desktop\wenli2.jpg');
gray=rgb2gray(I);
X=double(gray);
% load woman;
%单尺度二维离散小波分解。分解小波函数haar
[cA,cH,cV,cD]=dwt2(X,'haar');
%单尺度二维离散小波重构(逆变换)，升低频降高频
Y=idwt2(1.2*cA,0.6*cH,0.6*cV,0.6*cD,'haar');
figure;
subplot(1,2,1),imshow(uint8(X)),title('原始图像');
subplot(1,2,2),imshow(uint8(Y)),title('增强图像');