Patent ID: 6885767

Claim:
A device for use with a camera for creating a digital mask of a scene for discriminating between an object and a background, said camera having a lens with an iris and a principal axis, said iris having an iris diameter, said device comprising: a reflection box; a light trap; a beam-splitter mounted in said reflection box; a light source for projecting a light beam onto said beam-splitter; a light-source aperture deployed between said light source and said beam-splitter; an adjustable mount for adjusting a position of said light source relative to said beam-splitter in any of three mutually perpendicular directions; wherein sold reflection box has a front face and a rear face, said front face having a front upper edge and said near face having a rear upper edge and a rear lower edge, wherein said beam-splitter is planar and is mounted in said reflection box so as to extend substantially between said front upper edge and said rear lower edge, wherein said light trap is a substantially planar, rigid element, having a front trap edge, a rear trap edge, and two trap side edges, wherein said front trap edge is affixed to said front upper edge, and said rear trap edge is raised above said rear upper edge; and wherein said camera is mountable on said reflection box such that said principal axis passes through said beam-splitter, with said light beam from said light source incident on said beam-splitter at an angle of 90° to said principal axis.