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. 19, 2013
Filed:
Oct. 23, 2009
Applicant:
Koji Harada, Yokohama, JP;
Inventor:
Koji Harada, Yokohama, JP;
Assignee:
Canon Kabushiki Kaisha, , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06F 21/00 (2006.01); G02F 1/035 (2006.01);
U.S. Cl.
CPC ...
Abstract
Character spacing values in a document image are extracted and a variance is calculated for fluctuations in the character spacing values. When the calculated variance is lower than a preset threshold value, the document image is determined as having watermark information embedded therein. Such use of the variance in the character spacing values enables high-speed determination of the presence or absence of character-spacing watermark information. At this time, it is possible to speed up the determination by using only some character spacing values in the document, instead of using all character spacing values.