Wallpaper matting is a computer graphics technique used to extract regions from images. It is used in the NgC Content (National Geographic Content) for the purpose of segmenting images into distinct regions and objects. This technique is used to separate the foreground from the background in photos, as well as to split multiple objects in a single image. It works by using a statistical model to identify regions of similar color or texture, and then using a graph-based algorithm to separate them.