How to load an 8-bit image and output an overlay with Comments in c++ using the BMP format and openCV library:

One image (out1) that contains the original image overlaid (IO) with the overlay image. While there are several useful ways of overlaying, the one that you need to implement is the following: if a pixel is black in the overlay image, the corresponding pixel in out1 is white. If a pixel is not black in the overlay image, the corresponding pixel in out1 equals the corresponding pixel in the original image. We will call this way of processing image overlay (IO).