Abstract

In document scanning, integrating cavity effect (ICE) is defined as the increase in perceived reflectance of the imaged portion of a document due to the reflectance of the surrounding portion of that document. ICE occurs when light reflected off various portions of the document is captured by the illumination subsystem and then is redirected back to the imaged document area. This additional light is perceived by the imaging subsystem as an increase in document reflectance. In typical document scanners the perceived reflectance can change by as much as 20%, depending upon the “average” reflectance of the surrounding area. The illuminator characteristic that determines the level of ICE present is known as the illuminator kernel function, or One Trip Spread Function (OTSF).

© 1998 Optical Society of America