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:
Sep. 14, 1993
Filed:
Apr. 08, 1992
Fuji Xerox Co., Ltd., Tokyo, JP;
Abstract
A ground detection means 10 for detecting the ground level of a document and a data correction means 11 for calculating correction data based on the detected ground level are provided. The ground level of the document is detected by prescanning and the correction data is calculated therefrom so that parameters of color conversion means 2, 3 are changed by the correction data. The correction data is set by approximating the detected ground level with a linear function. As a result of the above construction, the correction data is generated easily to thereby remove ground fog and exclude back-side images of the document. In addition, if the ground level is detected by a lightness signal L* and corrected by the lightness signal L* or a color-separated signal BGR, the correction can be achieved by correcting the parameters of a matrix that converts the color-separated signals B, G, R to a system value (L*a*b*) signal.