## Multiply Image with a mask

### Ann G (view profile)

on 4 Nov 2015
Latest activity Commented on by Ann G

on 5 Nov 2015

### Thorsten (view profile)

I have a specific Dicom image (uint16) and i want to multiply it with a mask (double) and then use the final image to generate other information. As I know it is better if an image is uint16 than double but in order to multiply those two i have to convert one of them as uint16 or double..My code works right only when i turn my image into double, otherwise it returns me black image..Is there any differnece between double and uint16 images?What can I do to make my code work right and have uint16 image??

### Thorsten (view profile)

on 4 Nov 2015
Edited by Thorsten

### Thorsten (view profile)

on 4 Nov 2015

You can convert the mask to uint16:
X = uint16(2^16*rand(10)); % sample image
M = zeros(size(X)); M(4:6, 6:8) = 1; % create sample mask
Y = uint16(M).*X; % combine image and mask

Ann G

### Ann G (view profile)

on 5 Nov 2015
unfortunately it still returns me black image!! Thanks anyway!! I guess I'll work on double image!
Thorsten

### Thorsten (view profile)

on 5 Nov 2015
Maybe it just looks black. If you use imshow, the default range from black to white is 0..65535. You can use imshow(X, []) to adapt the range to the values in the image.
Ann G

### Ann G (view profile)

on 5 Nov 2015
I've checked the values and they are all 0.There must be something wrong when I multiply them..My results though are correct even with double image..