Display Individual Pixels in WPF

I have an application that needs to highlight individual pixels on an image. I don't want to edit the image, I just want to temporarily display red dots on top of certain pixels in the image. So far I have been using a Canvas to draw a whole lot of really small rectangles to highlight those pixels, but that has performance issues, and I was wanting to know if there w开发者_如何转开发as a better way to do it.

You can place another image layer over the original one with a transparent background and simply put red pixels on it.