高斯模板

源代码一：

clear all;
close all;
% 不处理边缘的高斯滤波，对应文档的方案一
originimg=imread('lena.jpg');
originimg=rgb2gray(originimg);
[ori_row,ori_col]=size(originimg);

sigma = 1.6;      %sigma赋值
N = 7;            %大小是（2N+1）×（2N+1）
N_row = 2*N+1;

OriImage_noise = imnoise(originimg,'gaussian'); %加噪

gausFilter = fspecial('gaussian',[N_row N_row],sigma);      %matlab 自带高斯模板滤波
blur=imfilter(OriImage_noise,gausFilter,'conv');

H = [];                                        %求高斯模板H
for i=1:N_row
    for j=1:N_row
        fenzi=double((i-N-1)^2+(j-N-1)^2);
        H(i,j)=exp(-fenzi/(2*sigma*sigma))/(2*pi*sigma);
    end
end
H=H/sum(H(:));              %归一化

desimg=zeros(ori_row,ori_col);            %滤波后图像
for i=1:ori_row                           
    for j=1:ori_col
        desimg(i,j)=OriImage_noise(i,j);
    end
end

temp=[];
for ai=N+1:ori_row-N-1
    for aj=N+1:ori_col-N-1
        temp=0;
        for bi=1:N_row
            for bj=1:N_row
                temp= temp+(desimg(ai+bi-N,aj+bj-N)*H(bi,bj));
            end
        end
        desimg(ai,aj)=temp;
    end
end
desimg=uint8(desimg);


subplot(2,2,1);imshow(originimg);title('原图');
subplot(2,2,2);imshow(OriImage_noise);title('噪声图');
subplot(2,2,3);imshow(desimg);title('myself高斯滤波');
subplot(2,2,4);imshow(blur);title('matlab高斯滤波')

源代码二：

clear all;
close all;
% 扩展原图像的高斯滤波，对应文档的方案2
originimg=imread('lena.jpg');
originimg=rgb2gray(originimg);
[ori_row,ori_col]=size(originimg);

sigma = 1.6;      %sigma赋值
N = 7;            %大小是（2N+1）×（2N+1）
N_row = 2*N+1;

OriImage_noise = imnoise(originimg,'gaussian'); %加噪

gausFilter = fspecial('gaussian',[N_row N_row],sigma);      %matlab 自带高斯模板滤波
blur=imfilter(OriImage_noise,gausFilter,'conv');

H = [];                                        %求高斯模板H
for i=1:N_row
    for j=1:N_row
        fenzi=double((i-N-1)^2+(j-N-1)^2);
        H(i,j)=exp(-fenzi/(2*sigma*sigma))/(2*pi*sigma);
    end
end
H=H/sum(H(:));              %归一化

desimg=zeros(ori_row,ori_col);            %滤波后图像
midimg=zeros(ori_row+2*N,ori_col+2*N);    %中间图像
for i=1:ori_row                           %原图像赋值给中间图像，四周边缘设置为0
    for j=1:ori_col
        midimg(i+N,j+N)=OriImage_noise(i,j);
    end
end
temp=[];
for ai=N+1:ori_row+N
    for aj=N+1:ori_col+N
        temp_row=ai-N;
        temp_col=aj-N;
        temp=0;
        for bi=1:N_row
            for bj=1:N_row
                temp= temp+(midimg(temp_row+bi-1,temp_col+bj-1)*H(bi,bj));
            end
        end
        desimg(temp_row,temp_col)=temp;
    end
end
desimg=uint8(desimg);

subplot(2,2,1);imshow(originimg);title('原图');
subplot(2,2,2);imshow(OriImage_noise);title('噪声图');
subplot(2,2,3);imshow(desimg);title('myself高斯滤波');
subplot(2,2,4);imshow(blur);title('matlab高斯滤波');