Curved Color Separation Spaces for Blue Screen Matting

This paper proposes a new blue screen matting digital solution, which employs “curved separating surfaces” in RGB colorspace. The “separating surface” model was examined by Jim Blinn and Alvy Ray Smith at the 1996 Siggraph conference and is the recognized model employed in two of the most common matting products used by the industry today. With this paper, we extend the concept from the earlier model, which was defined with coarse polygons, to curved surfaces that maintain a more natural pixel distribution of the foreground data against the background screen. A constrained grid surface patch (referred to as OGP) is introduced, which achieves a fast, practical computing solution for natural matte generation and background suppression. An additional solution called the extended matting problem is also presented that uses two additional curved separating surfaces for background spill removal.