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. 18, 2003
Filed:
Sep. 01, 1998
Applicant:
Inventors:
Yuichi Ikeda, Numazu, JP;
Nobuatsu Sasanuma, Mishima, JP;
Tetsuya Atsumi, Susono, JP;
Yasuhiro Saito, Shizuoka-ken, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04N 1/407 ; H04N 1/409 ; H04N 1/58 ; G06K 1/502 ;
U.S. Cl.
CPC ...
H04N 1/407 ; H04N 1/409 ; H04N 1/58 ; G06K 1/502 ;
Abstract
When pixels in a two-dimensional matrix are divided into lines A and B in the column (or row) direction (sub-scanning direction) and two neighboring pixels in the row (or column) direction are subjected to gradation correction respectively using characteristic curves for lines A and B, the characteristic curve for line B unpreferably has a stepwise characteristic portion having a step when it is stored in an LUT, due to quantization errors unique to digital values. Hence, the characteristic curve for line A is set to be decreased by the amount corresponding to the step.