Separations or images relating to film or other fields may be registered using a variety of features, such as, for example: (1) correcting one or more film distortions; (2) automatically determining a transformation to reduce a film distortion; (3) applying multiple criteria of merit to a set of features...http://www.google.com/patents/US7092584?utm_source=gb-gplus-sharePatent US7092584 - Registration of separations
