1.图像反转
MATLAB程序实现如下：
I=imread('xian.bmp');
J=double(I);
J=-J+(256-1);　　　　　　　　 %图像反转线性变换
H=uint8(J);
subplot(1,2,1),imshow(I);
subplot(1,2,2),imshow(H);(1. image reversal
The MATLAB program is implemented as follows:
I=imread ('xian.bmp');
J=double (I);
J=-J+ (256-1);% image inversion linear transformation
H=uint8 (J);
Subplot (1,2,1), imshow (I);
Subplot (1,2,2), imshow (H);)