Replace a certain color of pixels in a png with another png image

Question

I have a png (items.png) which consists of mostly black pixels.

I want to replace all the black pixels with another image. (background.png)

The images are not the same size, items.png is smaller than background.png.

Is there an ImageMagick command that does something like this?

Thanks!

Answer 1

Wow I should have read the man page for convert more thoroughly.

The answer is

convert -flatten background.png items.png out.png