White reference calibration in a dual digitizer

摘要

A dual digitizer for digitizing both transparent and reflective data mediums is provided where light from the reflective illuminator reflects off the transparent illuminator when the transparent illuminator is off to provide a white reference signal for use in calibrating the dual digitizer. A method of calibrating a dual digitizer for reflective scans includes: digitizing a transparent data medium; calibrating the dual digitizer to establish a white reference signal, the calibrating step including generating a light beam, reflecting a first portion of the light beam off a transparent illuminator, and utilizing the first portion of said light beam to establish the white reference signal; and digitizing a reflective data medium. The dual digitizer may be used in medical applications to digitize a transparent data medium such as an X-ray film.