How to “zero” everything within a masked part of an image in OpenCV

Question

If I have an image (IplImage 8-bit) and a binary mask (which is also an 8-bit IplImage of the same size, where every pixel has a value of either 0 or 255), how can I make every

Answer 1

Multiply or bit-and the mask with the image. There are some OpenCV functions for that, but I do not know their names for the C interface.

in C++:

Mat image, mask;

image = image * mask;
// or 
image = image & mask;