A system produces a standardized image of an object from an intermediate object recorded on film. An image of a spectrum of the light source illuminating the object is recorded on the film together with the image of the object. The image of the spectrum on the film is recorded by a film scanner and compared...http://www.google.se/patents/US5157506?utm_source=gb-gplus-sharePatent US5157506 - Standardized color calibration of electronic imagery
