How to select a roi in greyscale image and put values to zero?
Hello, i have a 12bit greyscale image (tiff) which I want to be able to draw a rectangular roi and fill these values to zero (i.e. black) This is my code, I cannot see where I am going wrong Raw=getimage(handles.axes1); % get image from axes component (im using GUIDE) h = imrect(handles.axes1); % User definable rectangle position=wait(h) p = h.getPosition(); position=[p(1) p(2) p(3) p(4)]; % [xmin ymin width height] delete(h); Raw(p(2):(p(2)+p(4)),p(1):(p(1)+p(3)))==0; % put user specified roi to 0 (black) axes(handles.axes1); cla reset; % Clear current axes imshow(Raw) % Draw modified image
Kshitij Singh answered .
2025-11-20
Use = to assign, not == which is a comparison.
Raw(p(2):(p(2)+p(4)), p(1):(p(1)+p(3))) = 0;
mask = h.createmask(); Raw(mask) = 0;