Target for Scanner Diagnostics and Calibration
Original Publication Date: 1978-Sep-01
Included in the Prior Art Database: 2005-Feb-21
Optical scanners often need to be calibrated. This is a process in which correction factors for each pel (picture element) are generated so that ensuing documents produce a uniform output for a uniform input. Traditionally, at the beginning of some scanning session, a white document is scanned, and the correction factors are generated and stored away. Sometimes it is also necessary to scan a black sheet to calibrate the dark level output of the scanner.