MATLAB: How to combine image with mask

Question

hi , i read a image and want combine with mask that contain a line on it , i make a mask but i can't combine a image and mask that show line on the reading image

   im=imread('apple.jpg');
       mask=255*zeros(size(im));
       mask=insertShape(mask,'line',[50 50  250 250],'linewidth',10,'color',[255 255 0]);
       mask=uint8(mask);
       subplot(1,3,1);
       imshow(im);
       title('original');
       subplot(1,3,2);
       imshow(mask);
%    how to combine im and mask
%    im3 = combine(im , mask)
       subplot(1,3,3)
       imshow(im3);
       title('combine')

how can i do this and show line mask on original image?

Answer 1

im3 = im;
im3(mask ~= 0) = mask(mask ~= 0);