Transfer Binary ROI to a raw 12bit image

Hi. I have a 12bit grayscale image (of white dots on a black background) that I binarise. Is it possible to create circular ROI's around the binary image features and trasnfer these back onto the raw 12 bit image. This is what I have so far>

    bw = im2bw(I, graythresh(I));
    axis off;
    imshow(bw)
    %-------------------------------------------------------
    bw4_perim = bwperim(bw);
    CC=bwconncomp(bw4_perim);  %This is a struct, so access only the number
    num = CC.NumObjects;
    set(handles.editCount,'String', num2str(num));

    axes(handles.axes3)
    imshow(I,[])
    hold on
    spy(bw4_perim)

Answer 1

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_do_I_create_a_circle.3F

Once you have the binary circle created in the appropriate positions, multiply the roi mask by (2^12 - 1) to get the 12-bit grayscale image.