空域濾波.doc

空域濾波空域濾波器分為：平滑空間濾波器和銳化空間濾波器在數(shù)字圖像處理中，常用的噪聲有：加性噪聲、乘性噪聲、椒鹽噪聲。一、平滑濾波器1、 平滑線性濾波器2、 中值濾波3、 維納自適應濾波器二、銳化濾波器1、梯度法2、拉普拉斯運算例1：圖像噪聲的添加clear all I=imread(eight.tif); J1=imnoise(I,gaussian); J2=imnoise(I,salt & pepper,0.02); J3=imnoise(I,speckle); subplot(2,2,1); imshow(I); title(原始圖像); subplot(2,2,2); imshow(J1); title(加入高斯噪聲圖像); subplot(2,2,3); imshow(J2); title(加入椒鹽噪聲圖像);subplot(2,2,4); imshow(J3); title(加入隨機噪聲圖像);例2：均值濾波器clear allI=imread(cameraman.tif);H1=ones(3)/9;%創(chuàng)建均值濾波模板H2=ones(7)/49;%創(chuàng)建均值濾波模板J=imnoise(I,gaussian,0,0.02);J=double(J);%均值濾波G1=conv2(J,H1, same);G2=conv2(J,H2, same); subplot(2,2,1); imshow(I); title(原始圖像); subplot(2,2,2); imshow(J,); title(加入高斯噪聲圖像); subplot(2,2,3); imshow(G1,); title(3*3均值濾波圖像);subplot(2,2,4); imshow(G2,); title(7*7均值濾波圖像);例3：超限像素平滑法clear allI=imread(cameraman.tif);m n=size(I);T=50;%設(shè)定閾值G=;H1=ones(3)/9;%創(chuàng)建均值濾波模板J=imnoise(I,salt & pepper,0.05);J=double(J);%均值濾波G1=conv2(J,H1, same);%超限像素平滑for i=1:mfor j=1:nif abs(J(i,j)-G1(i,j)TG(i,j)=G1(i,j);elseG(i,j)= J(i,j);endendend subplot(2,2,1); imshow(I); title(原始圖像); subplot(2,2,2); imshow(J,); title(加入椒鹽噪聲圖像); subplot(2,2,3); imshow(G1,); title(3*3均值濾波圖像);subplot(2,2,4); imshow(G,); title(超限像素平滑圖像);例4：中值濾波clear allI=imread(eight.tif);N1=imnoise(I,salt & pepper,0.04);N2=imnoise(I,gaussian,0,0.02);N3=imnoise(I,speckle,0.02);G1=medfilt2(N1);G2=medfilt2(N2);G3=medfilt2(N3); subplot(2,3,1); imshow(N1); title(加入椒鹽噪聲圖像); subplot(2,3,2); imshow(N2); title(加入高斯噪聲圖像); subplot(2,3,3); imshow(N3); title(加入乘性噪聲圖像);subplot(2,3,4); imshow(G1); title(椒鹽噪聲中值濾波圖像);subplot(2,3,5); imshow(G2); title(高斯噪聲中值濾波圖像);subplot(2,3,6); imshow(G3); title(乘性噪聲中值濾波圖像);例5：用ordfilt2函數(shù)實現(xiàn)圖像統(tǒng)計濾波clear allI=imread(eight.tif);N1=imnoise(I,salt & pepper,0.04);G1=ordfilt2(N1,1,ones(3);G2=ordfilt2(N1,5,ones(3);G3=ordfilt2(N1,9,ones(3); subplot(2,2,1); imshow(N1); title(加入椒鹽噪聲圖像); subplot(2,2,2); imshow(G1); title(最小值濾波圖像); subplot(2,2,3); imshow(G2); title(中值濾波圖像);subplot(2,2,4); imshow(G3); title(最大值濾波圖像);例5：維納濾波I=imread(cameraman.tif);N1=imnoise(I,gaussian,0,0.005);J1=wiener2(N1,5 5); subplot(1,2,1); imshow(N1); title(加入高斯噪聲圖像); subplot(1,2,2); imshow(J1); title(維納濾波圖像);例6：梯度法銳化圖像I=imread(cameraman.tif); subplot(2,3,1); imshow(I); title(原始圖像);I=double(I);Gx,Gy=gradient(I);%計算梯度G=sqrt(Gx.*Gx+Gy.*Gy);%求梯度幅度J1=G;%直接顯示梯度 subplot(2,3,2); imshow(J1,); title(梯度增強顯示方法一);T=20;J2=I;K=find(G=T);J2(K)=G(K); subplot(2,3,3); imshow(J2,); title(梯度增強顯示方法二);LG=255;J3=I;K=find(G=T);J3(K)=LG; subplot(2,3,4); imshow(J3,); title(梯度增強顯示方法三);J4=zeros(size(I);%等于LB=0；J4=LB*IK=find(G=T);J4(K)=G(K); subplot(2,3,5); imshow(J4,); title(梯度增強顯示方法四);J5=zeros(size(I);%等于LB=0；J4=LB*IK=find(G=T);J5(K)=LG; subplot(2,3,6); imshow(J5,); title(梯度增強顯示方法五);例7：拉普拉斯算子增強圖像I=imread(tire.tif