How to overlay another image on top?

Question

WPF

There is an image, how to insert another image into it with a white / black background, so that this background dissolves. Like layers in Photoshop.
There is a picture image, and there is a contour of this image, how to impose a contour on this image?
I know how to do it through the code , but for me, (decompose into bytes and overlay it on top, but this is not optimal, since I will redraw the base image,
but I just feel that it’s possible in 1-2 lines. methods PushOpacityMask(brush) PushOpacity palette mask