MATLAB: Convert the intensity of image into a specific intensity range

Question

Hello everybody,

I have 100 3D medical images that have different intensity ranges. most of them have a maximum intensity of 255( and their type is single) but that of some of them is about 2000-3000( uint16). How can I convert the intensity of all images into [0,255]?

I tried this: 255*( (Img – min(Img(:)))./max(img(:))) but it didn't give the expected result. please help me with this problem.

Thank you.

Answer 1

You can use mat2gray:

Img2 = uint8(255 * mat2gray(Img));

or you can use rescale

Img2 = rescale(Img, 0, 255);

rescale gives a floating point output. Cast to uint8 if you want uint8. Pick whatever min and max you want. We can give a better answer if you tell us why the code you used did not give the expected answer.