![](https://csdnimg.cn/release/download_crawler_static/87048531/bg9.jpg)
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Adjust image intensity values or colormap 图像灰度值或 colormap 调整
% J = IMADJUST(I,[LOW_IN; HIGH_IN],[LOW_OUT; HIGH_OUT])
>> subplot(232);imshow(j);title('线性扩展');
>> i1=double(i);i2=i1/255;c=2;k=c*log(1+i2);
>> subplot(233);imshow(k);
>> title('非线性扩展');
>> m=255-i;
>> subplot(234);imshow(m)
>> title('灰度倒置')
>> n1=im2bw(i,.4);n2=im2bw(i,.7);
>> subplot(235);imshow(n1);title('二值化阈值 0.4')
>> subplot(236);imshow(n2);title('二值化阈值 0.7')
图像的代数运算
加。减,乘法(获取感兴趣的区域)
imresize 放大
a=imresize(I,2) %比例
a=imresize(I,[33 24]) %非比例
imrotate 旋转
a=imrotate(I,45)
时域旋转多少度,频域也就旋转多少度
>> i=zeros(256,256);
>> i(88:168,124:132)=1;
>> imshow(i)
>> j=fft2(i);f=abs(j);j1=fftshift(f);figure;imshow(j1,[5 50])
>> j=imrotate(i,90,'bilinear','crop');
>> figure;imshow(j);