数字图像处理实验

（1）矩阵图像的傅里叶变换

f=zeros(30,30);

f(5:24,13:17)=1;

imshow(f,'notruesize')

F=fft2(f);

F2=log(abs(F));

figure;imshow(F2,[-1 5],'notruesize');colormap(jet);colorbar;

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11.522.533.544.5

（2）图像的傅里叶变换

I=imread('concordorthophoto.png'); imshow(I);

B=ffshift(fft2(I)); figure;

imshow(log(abs(B)),[]),colorbar;

图像离散余弦变换

RGB=imread('hestain.png');

I=rgb2gray(RGB);

imshow(RGB);

J=dct2(I);

figure,imshow(log(abs(J)),[]),colorbar; J(abs(J)<10)=0;

K=idct2(J)/255;

figure,imshow(K)

二(1)

直方图均衡化增强图像对比度程序I=imread('trees.tif');

J=imnoise(I,'salt & pepper',0.02); imshow(I);figure,imshow(J)

K1=filter2(fspecial('average',3),J)/255; K2=filter2(fspecial('average',5),J)/255; K3=filter2(fspecial('average',7),J)/255; figure,imshow(K1)

figure,imshow(K2)

figure,imshow(K3)

二（2）

I=imread('trees.tif');

J=imnoise(I,'salt & pepper',0.02); imshow(I);figure,imshow(J)

K1=medfilt2(J,[3 3]);

K2=medfilt2(J,[5 5]);

K3=medfilt2(J,[7 7]);

figure,imshow(K1)

figure,imshow(K2)

figure,imshow(K3)

二（3）

维纳滤波

I=imread('liftingbody.png');

J=imnoise(I,'gaussian',0,0.005); imshow(I);figure,imshow(J)

K1=wiener2(J,[5 5]);

figure,imshow(K1)

二（4）

高斯滤波

I=imread('kids.tif');

J=imnoise(I,'gaussian',0,0.005); imshow(I);figure,imshow(J)

h=fspecial('gaussian');

K=filter2(h,J)/255;

figure,imshow(K)

(1)锐化滤波

I=imread('circuit.tif');

h=fspecial('laplacian');

J=filter2(h,I);

imshow(I),figure,imshow(J)

(2)几种边缘算子

I=imread('circuit.tif');

h1=fspecial('sobel');

J1=filter2(h1,I);

h2=fspecial('prewitt');

J2=filter2(h2,I);

h3=fspecial('log');

J3=filter2(h3,I);

imshow(I),figure,imshow(J1)

figure,imshow(J2),figure,imshow(J3)

2、图像分割

（1）灰度阈值分割法

（5）边缘检测

3、图像压缩编码

（2）离散余弦变换