Of course (see above). Now you need to think about details.

When you say Black & White, do you mean bitonal 1-bit color, or greyscale?

Does a 32bit-color image count as B&W if the only colors used are Black + White? Does it count if the saturation of every pixel is (close to?) zero? (IE greys)

Would you count a sepia tone image, which is basically greyscale with the blue reduced or removed. (All hues are the same)