MATLAB对图形做数值变换

I = imread('eight.tif');
c = [222 272 300 270 221 194];
r = [21 21 75 121 121 75];
J = roifill(I,c,r);
imshow(I)
figure, imshow(J)

I = imread('cameraman.tif');
J = imadjust(I,[0 0.2],[0.5 1]);
%变换[0 0.2]--->[0.5 1]
imshow(I)
figure, imshow(J)

MATLAB图像处理—孙兆林编著—清华大学出版社