Giving specific values to pixels in some selected region

Question

I'm trying to do the following in MATLAB:

• Select some region of interest
• Give the pixels in that region the value 1 for instance

I'm not sure, would imfreehand be a starting point here for selecting the region of interest. What then?

How can this be done in MATLAB?

Thanks.

Answer 1

Here is a short sample. Since you mentioned imfreehand, I included that but depending on what type of ROI you want to create, impoly or imrect may do a better job:

img = im2double(imread('cameraman.tif'));
imshow(img);
roi = imfreehand;
img2 = img;
img2(roi.createMask) = 1;
imshow(img2);