Unzip the contents into your ComfyUI\custom_nodes folder and restart ComfyUI and refresh your browser. The new node should show up under image in the UI. This node will take the provided image and combines a few of the other nodes I have to make it a single step process to make a contrast mask from it. This can be used for background replacement if you have an image with a good depth mask applied such as one that came from MiDaS or just a normal high contrast background.

