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:
Apr. 16, 2013
Filed:
Nov. 29, 2010
Kenichi Okihara, Yokosuka, JP;
Koji Harada, Yokohama, JP;
Junichi Hayashi, Kamakura, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An apparatus and method specify the presence/absence of an alteration and an alteration position of an image. A block-division unit divides image data into image data of a first unit including a predetermined number of pixels. A block calculation unit calculates an image data coefficient of the first unit. A cell-division unit divides one image data of the first unit into image data of a second unit. A cell calculation unit calculates an image data coefficient of the second unit. First verification data is generated by selecting two image data coefficients of the first unit and generating, for one pair, data representing the magnitude relation of the image data coefficients of the first unit. Second verification data is generated by selecting two image data coefficients of the second unit and generating, for one pair, data representing the magnitude relation of the image data coefficients of the second unit.