ch10_2_3.m

常用图像处理源码合集

%窗口法
%利用函数find1
Hd = zeros(11,11); Hd(4:8,4:8) = 1;
[f1,f2] = freqspace(11,'meshgrid');
mesh(f1,f2,Hd);
axis([-1 1 -1 1 0 1.2]), colormap(jet(64))
h = fwind1(Hd,hamming(11));
figure, freqz2(h,[32 32]);
axis([-1 1 -1 1 0 1.2])

%利用函数find2
%生成给定的频率响应矩阵Hd
[f1,f2] = freqspace(21,'meshgrid');
Hd = ones(21); 
r = sqrt(f1.^2 + f2.^2);
Hd((r<0.1)|(r>0.5)) = 0;
colormap(jet(64))
mesh(f1,f2,Hd)
%生成指定的窗口
win = fspecial('gaussian',21,2);
win = win ./ max(win(:));  % 归一划最大窗口值
mesh(win)
%得到所需的2-D FIR滤波器频率
h = fwind2(Hd,win);
freqz2(h)%计算h的频率响应