What's an efficient way to tell if a bitmap is entirely black?

Question

I\'m wondering if there\'s a super-efficient way of confirming that an Image object references an entirely black image, so every pixel within the bitmap is ARGB(255, 0, 0, 0).

Answer 1

To be entirely sure of the image's blackness, you will have to check every pixel, and accessing the pixel data in an unsafe block is likely the fastest way to do it. Of course it's possible to optimize for the non-black case and try to find those earlier, but in the worst case you'll always have to check each and every pixel.