The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 14, 2000
Filed:
Aug. 24, 1994
Bart D Selby, Walworth, NY (US);
Thomas R Beikirch, Webster, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
The present invention is a method of compensating for the offset present in image signals produced by an image processing apparatus, and more particularly to accurately characterizing the offset, gain and higher order responses of image sensing elements to enable correction thereof in an image sensing device or scanner. The method utilizes intermediate (grey) reflectance targets to measure the response of each sensor element and then, using the measured responses, fits a characteristic curve to the responses to calculate the response of the sensor element, including a zero reflectance situation, to characterize an accurate offset level, gain, and higher order response for the sensor. Moreover, additional reflectance targets and response may be employed so as to enable the characterization of image sensing elements exhibiting non-linear responses to linearly increasing light intensities.