matlab-理想低通滤波算法

clear all;

close all;

P=input('input image data:');

d=size(P);

if(d(3)>1)

P=rgb2gray(P);

end

subplot(131);imshow(P);

title('原始图像');

P1=imnoise(P,'salt & pepper',0.02);

subplot(132)

imshow (P1);

title('加入椒盐噪声后的图像');

f=double(P1);

g=fft2(f);%傅里叶变换

g=fftshift(g);%转换数据矩阵

[M,N]=size(g);

D0=input('input nonnegative dhreshold D0='); n1=fix(M/2);

n2= fix(N/2);

for i=1:M

for j=1:N

d=sqrt((i-n1)^2+(j-n2)^2);

if d<=D0 h=1;

else h=0;

%计算Ideal低通转换函数

end

result(i,j)=h*g(i,j);

end

end

result=ifftshift(result);

X2=ifft2(result);

X3=uint8(real(X2));

subplot(133)

imshow (X3);

title('理想低通滤波所得图像');