数字图像处理.docx
- 文档编号:11279774
- 上传时间:2023-02-26
- 格式:DOCX
- 页数:28
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数字图像处理.docx
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数字图像处理
1图象的读写
a)图象读
>>img1=imread('D:
\photos\5.bmp');
>>imshow(img1);
b)图象写
>>[X,map]=imread('D:
\photos\5.bmp');
>>imwrite(X,map,'D:
\photos\text5.bmp');
c)图象文件格式转换
>>bitmap=imread('5.bmp','bmp');
>>imwrite(bitmap,'test5.png','png');
2图象显示
a)二进制图象的显示
>>BW1=zeros(20,20);
>>BW1(2:
2:
18,2:
2:
18)=1;
>>imshow(BW1)
whos
NameSizeBytesClass
BW120x203200doublearray
X592x500296000uint8array
bitmap40x40x34800uint8array
img1592x500296000uint8array
map256x36144doublearray
Grandtotalis597968elementsusing606144bytes
>>BW2=uint8(BW1);
>>figure,imshow(BW2)
>>BW3=BW2~=0;
>>figure,imshow(BW3)
>>whos
NameSizeBytesClass
BW120x203200doublearray
BW220x20400uint8array
BW320x20400logicalarray
X592x500296000uint8array
bitmap40x40x34800uint8array
img1592x500296000uint8array
map256x36144doublearray
Grandtotalis598768elementsusing606944bytes
>>BW=imread('5.bmp');
>>imshow(BW);
>>figure,imshow(~BW);
>>figure,imshow(BW,[100;001]);
b)灰度图象的显示
>>I=imread('5.bmp');
>>J=filter2([12;-1-2],I);
>>imshow(I)
>>figure,imshow(J,[])
C)索引图像的显示
>>[X,map]=imread('5.bmp');
>>imwrite(X,map,'5.bmp');
>>imshow(X)
>>figure,imshow(X,map)
d)RGB图像的显示
>>I=imread('3.jpg');
>>imshow(I)
>>RGB=imread('3.jpg');
>>figure,imshow(RGB)
>>figure,imshow(I(:
:
3))
e)多帧图像的显示
f)显示多幅图像
>>[X1,map1]=imread('5.bmp');
>>[X2,map2]=imread('7.bmp');
>>subplot(1,2,1),imshow(X1,map1)
>>subplot(1,2,2),imshow(X2,map2)
>>subplot(1,2,1),subimage(X1,map1)
>>subplot(1,2,2),subimage(X2,map2)
试验二
1图像的点运算
>>test=imread('2.bmp');
>>subplot(131),imshow(test)
>>I=double(test);
>>J=I*0.43+60;
>>test2=uint8(J);
>>subplot(132),imshow(test2)
>>J=I*1.5-60;
>>test3=uint8(J);
>>subplot(133),imshow(test3)
2图像的代数运算
a)图像的加法运算
f=imread('j1.jpg');
subplot(2,2,1),imshow(f)
f2=imread('j2.jpg');
subplot(2,2,2),imshow(f2)
k=imadd(f,f2);
subplot(2,2,3),imshow(k)
k2=imadd(f,f2,'uint16');
subplot(2,2,4),imshow(k2,[])
b)图像的减法运算
>>I=imread('9.tif');
>>imshow(I)
>>background=imopen(I,strel('disk',15));
>>figure,imshow(background);
>>I2=imsubtract(I,background);
>>figure,imshow(I2)
C)图像乘法运算
>>I=imread('11.tif');
>>J=immultiply(I,1.2);
>>K=immultiply(I,0.5);
>>imshow(I)
>>figure,imshow(J)
>>figure,imshow(K)
>>I=imread('11.tif');
>>I16=uint16(I);
>>J=immultiply(I16,I16);
>>figure,imshow(I),figure,imshow(J)
3图像的几何运算
a)改变图像的大小
>>I=imread('5.bmp');
>>J=imresize(I,1.5);
>>K=imresize(I,0.5);
>>imshow(I)
>>figure,imshow(J)
>>figure,imshow(K)
>>Y=imresize(I,[100,150]);
>>figure,imshow(Y)
b)旋转一幅图像
>>I=imread('5.bmp');
>>J=imrotate(I,30,'bilinear');
>>J1=imrotate(I,30,'bilinear','crop');
>>imshow(I)
>>figure,imshow(J)
>>figure,imshow(J1)
>>J2=imrotate(I,-15,'bilinear');
>>figure,imshow(J2)
c)图像的剪切
>>I=imread('5.bmp');
>>imshow(I);
>>I1=imcrop;
>>I1=imcrop;
>>figure,imshow(I1)
>>I2=imcrop(I,[3060120160]);
>>figure,imshow(I2)
实验三
傅里叶变换:
a)绘制一个二维图像矩阵
f=zeros(30,30);
>>f(5:
24,13:
17)=1;
>>imshow(f,'notruesize')
>>F=fft(f);
>>F2=log(abs(F));
>>figure,imshow(F2,[-15],'notruesize');
>>colormap(jet);
F=fft2(f,256,256);
>>figure,imshow(log(abs(F)),[-1,5]);
>>colormap(jet);
F2=fftshift(F);
>>figure,imshow(log(abs(F2)),[-1,5]);
>>colormap(jet);colorbar
b.傅里叶变换分析两图像的相关性:
bw=imread('3.bmp');
a=bw(59:
71,81:
91);
imshow(bw);
figure,imshow(a);
c=real(ifft2(fft2(bw).*fft2(rot90(a,2),256,256));figure,imshow(c,[]);
thresh=max(c(:
));
figure,imshow(c>thresh-10);
figure,imshow(c>thresh-15);
2.余弦变换a:
>>RGB=imread('autumn.tif');
>>imshow(RGB)
>>I=rgb2gray(f);
>>figure,imshow(I)
>>J=dct2(I);
>>figure,imshow(log(abs(J)),[]),colormap(jet(64));colorbar;
b.将小于10的系数舍弃重构图像:
f=imread('autumn.tif');
>>I=rgb2gray(f);
>>J=dct2(I);
>>figure,imshow(I)
>>k=idct2(J);
>>figure,imshow(k,[0255])
>>J(abs(J)<10)=0;
>>k2=idct2(J);
>>figure,imshow(k2,[0255])
c.dct变换进行图像压缩:
>>I=imread('cameraman.tif');
>>I=im2double(f);
>>T=dctmtx(8);
>>B=blkproc(f,[8,8],'P1*x*P2',t,t');
>>mask=[11110000;11100000;11000000;
10000000;00000000;00000000;00000000;
00000000];
>>B2=blkproc(b,[8,8],'P1.*x',mask);
>>I2=blkproc(b2,[8,8],'P1*x*P2',t',t);
>>imshow(f)
>>figure,imshow(I2)
实验四
1灰度变换增强
a)线段上像素分布
>>I=imread('liftingbody.png');
>>x=[1942741677];
>>y=[964623733];
>>improfile(I,x,y),gridon
b)直方图变换
i>>I=imread('14.jpg');
>>imshow(I)
>>figure,imhist(I,64)
>>figure,imhist(I,128)
ii
>>I=imread('14.jpg');
>>imshow(I)
>>figure,imhist(I)
>>J=imadjust(I,[0.150.9],[01]);
>>figure,imhist(J)
>>figure,imshow(J)
I=imread('cameraman.tif');
>>imshow(I)
>>figure,imhist(I)
>>J=imadjust(I,[00.2],[0.51]);
>>figure,imhist(J)
>>figure,imshow(J)
Iii
直方图均衡化:
I=imread('pout.tif');
>>imshow(I)
>>figure,imhist(I)
>>J=histeq(I);
>>figure,imhist(J)
>>figure,imshow(J)
>>I=imread('tire.tif');
>>imshow(I)
>>figure,imhist(I)
>>figure,imshow(J)
>>figure,imhist(J)
2空域滤波增强
A)噪声模拟
>>I=imread('eight.tif');
>>imshow(I)
>>I1=imnoise(I,'gaussian',0,0.01);
>>figure,imshow(I1)
>>I2=IMNOISE(I,'salt&pepper');
>>figure,imshow(I2)
B)空域滤波
i
>>I=imread('eight.tif');
>>J=IMNOISE(I,'salt&pepper',0.02);
>>imshow(J)
>>K1=medfilt2(J,[33]);
>>figure,imshow(K1)
>>K2=filter2(fspecial('average',5),J)/255;
>>figure,imshow(K2)
iii
>>I=imread('5.bmp');
>>imshow(I)
>>h=fspecial('laplacian');
>>I2=filter2(h,I);
>>figure,imshow(I2)
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- 数字图像 处理