Patent ID: 7084386

Claim:
A light source calibration target, comprising: a substrate having a substantially Lambertian surface; a plurality of reference marks formed on said surface that are visually distinct from said surface and comprising at least one visually distinct shape having corners formed on said surface so as to be visually distinct from said surface; and a plurality of three dimensional objects mounted on said surface each having an upstanding feature disposed above said surface; said light source calibration target for being disposed in a field of view of an image capture system that includes a camera to calibrate individual ones of a plurality of light sources by operating the camera to capture an image of the light source calibration target with an individual one of the light sources turned on, by constructing a plurality of lines each of which intersects the feature of an object and a point on a shadow cast by the feature, and by determining a location of the light source as a point of intersection of the plurality of lines, and further comprising determining a correction factor corresponding to a difference between a light source emission distribution and an ideal light source emission distribution.