Film scanner with dust and scratch correction by use of dark-field illumination

摘要

A method and apparatus for detecting surface defects and artifacts on a transmissive image in an optical image scanner and correcting the resulting scanned image. In one scan, the image is scanned normally. Surface defects and artifacts such as dust, scratches and finger prints are detected by providing a separate scan using infrared light or by measuring light (white or infrared) that is scattered or diffracted by the defects and artifacts. Separate optical paths for illumination may be used, or separate optical paths for intensity measurement may be used. Image processing may then be used to correct areas in the normal scan corresponding to defects identified in the separate scan.