clear all; %清空Matlab工作平台所有变量
%load wbarb; %小波变换边缘提取程序,load指从文件中装入数据
%I = ind2gray(X,map);%检索图转成灰度图
X=imread('3.4.bmp');
I = rgb2gray(X); %转成灰度图
figure;
imshow(I);
I1 = imadjust(I,stretchlim(I),[0,1]); %调整图像的像素值,可以改变对比度和颜色
figure; %生成图像窗口
imshow(I1);
[N,M] = size(I); %确定矩阵l的大小,N为128,M为128
h = [0.125,0.375,0.375,0.125];
g = [0.5,-0.5];
delta = [1,0,0]; %就是δ,在标注曲线坐标轴时用到,xlabel('偏移量\delta'),就把x轴标注成:'偏移量δ'
J = 2;
a(1:N,1:M,1,1:J+1) = 0; %和M是灰度图像I的像素值,1:N和1:M是从1到N,和从1到M形成的两维上的所有数值为0,a 是一个N*M*1*J+1的4维数组
dx(1:N,1:M,1,1:J+1) = 0;
dy(1:N,1:M,1,1:J+1) = 0;
d(1:N,1:M,1,1:J+1) = 0;
a(:,:,1,1) = conv2(h,h,I,'same'); %计算二维卷积
dx(:,:,1,1) = conv2(delta,g,I,'same');
dy(:,:,1,1) = conv2(g,delta,I,'same');
x = dx(:,:,1,1);
y = dy(:,:,1,1);
d(:,:,1,1) = sqrt(x.^2+y.^2); %sqrt为平方根函数,矩阵的乘
I1 = imadjust(d(:,:,1,1),stretchlim(d(:,:,1,1)),[0 1]);
figure;
imshow(I1);
lh = length(h); %求字符串长度lh=4
lg = length(g); %求字符串长度lg=2
for j = 1:J+1
lhj = 2^j*(lh-1)+1;
lgj = 2^j*(lg-1)+1;
hj(1:lhj)=0;
gj(1:lgj)=0;
for n = 1:lh
hj(2^j*(n-1)+1)=h(n); %尺度因子2j上的扩展函数
end
for n = 1:lg
gj(2^j*(n-1)+1)=g(n); %尺度因子2j上的扩展函数
end
a(:,:,1,j+1) = conv2(hj,hj,a(:,:,1,j),'same');
dx(:,:,1,j+1) = conv2(delta,gj,a(:,:,1,j),'same');
dy(:,:,1,j+1) = conv2(gj,delta,a(:,:,1,j),'same');
x = dx(:,:,1,j+1);
y = dy(:,:,1,j+1);
dj(:,:,1,j+1) = sqrt(x.^2+y.^2); %二维信号的模值
I1 = imadjust(dj(:,:,1,j+1),stretchlim(dj(:,:,1,j+1)),[0 1]); %Il是灰度图像矩阵,调整图像灰度值或颜色映射表
figure;
imshow(I1);
end