function combo(im,mask)
% combo - overlay a binary image on an image
% On input:
%     im (MxNxP array): digital image
%     mask (MxN array): binary image
% On output:
%     N/A
% Call:
%     combo(im,mask);
% author:
%     T. Henderson
%     UU
%     Fall 2019
%

[M,N,P] = size(im);

im = mat2gray(im);

if P==3
    imd = im;
else
    imd(:,:,1) = im;
    imd(:,:,2) = im;
    imd(:,:,3) = im;
end 

for r = 1:M
    for c = 1:N
        if mask(r,c)>0
            imd(r,c,1) = 255;
            imd(r,c,2) = 0;
            imd(r,c,3) = 0;
        end
    end
end

imshow(imd);
