從空間濾波器獲得頻率域?yàn)V波器

1、3-2從空間濾波器獲得頻率域?yàn)V波器一、實(shí)驗(yàn)?zāi)康恼莆諒目臻g濾波器獲得頻率域?yàn)V波器的方法二、實(shí)驗(yàn)內(nèi)容1 .從Sobel空間濾波器用freqz2獲得頻率域?yàn)V波器2 .觀察空間濾波器和對應(yīng)的頻率域?yàn)V波器的濾波結(jié)果三、實(shí)驗(yàn)步驟1 .執(zhí)行如下代碼，實(shí)現(xiàn)空間域?yàn)V波和頻域?yàn)V波的比較1讀入原始圖像：clcclearf=imread('lena.jpg'imshow(ftitle('原始圖像2進(jìn)行傅里葉變換：F=fft2(f;S=fftshift(log(1+abs(F;S=gscale(S;imshow(Stitle('傅立葉頻譜圖像原始圖像3使用f=im2double(f之后再

2、進(jìn)行處理的傅立葉頻譜圖像：f=im2double(f;%轉(zhuǎn)換為F=fft2(f;S=fftshift(log(1+abs(F;S=gscale(S;imshow(Stitle('使用f=im2double(f之后再進(jìn)行處理的傅立葉頻譜圖像'2.freqz2P90增強(qiáng)垂直邊緣sobelH=freqz2(h,PQ(1,PQ(2:1產(chǎn)生的濾波器原點(diǎn)在矩陣中心處讀入圖像：clcclearf=imread('lena.jpg'imshow(f進(jìn)行傅里葉變換：F=fft2(f;S=fftshift(log(1+abs(F;S=gscale(S;Imshow(S增強(qiáng)垂直邊緣：

3、h=fspecial('sobel”;增強(qiáng)垂直邊緣figure,freqz2(h;%usesn2n1=6464.PQ=paddedsize(size(f;H=freqz2(h,PQ(1,PQ(2;%產(chǎn)生的濾波器原點(diǎn)在矩陣中心處H1=ifftshift(H;%遷移原點(diǎn)到左上角figure,mesh(abs(H1(1:20:400,1:20:400imshow(abs(H,口imshow(abs(H1,口gs=imfilter(double(f,h;gf=dftfilt(f,H1;imshow(gs,口imshow(gf,口imshow(abs(gs,口imshow(abs(gf,口ims

4、how(abs(gs>0.2*abs(max(gs(:imshow(abs(gf>0.2*abs(max(gf(:d=abs(gs-gf;max(d(:min(d(:3.reqz2P90增強(qiáng)水平邊緣sobel%fft2(f產(chǎn)生的頻域F的原點(diǎn)在左上角讀入圖像clcclearf=imread('lena.jpg'傅里葉變換：F=fft2(f;S=fftshift(log(1+abs(F;S=gscale(S;h=fspecial('sobel'%增強(qiáng)水平邊緣figure,freqz2(h;%size_h=size(tempPQ=paddedsize(size(f;H=freqz2(h,PQ(1,PQ(2;H1=ifftshift(H;figure,mesh(abs(H1(1:20:400,1:20:400imshow(abs(H,口imshow(abs(H1,口gs=imfilter(double(f,h;gf=dffilt(f,H1;d=abs(gs-gf;max(d(:min(d(:四、實(shí)驗(yàn)總結(jié)通過本次實(shí)驗(yàn)，我了解了從空間濾波器