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:
Oct. 05, 2004
Filed:
Jan. 30, 2001
David J. Michael, Framinghan, MA (US);
Juha Koljonen, Needbon, MA (US);
Paul Dutta-Choudhury, Franklin, MA (US);
Cognex Corporation, Natick, MA (US);
Abstract
An efficient and reliable method and apparatus is disclosed that finds a reference point of an object profile within an image when the object is of an unknown size. The object profile is modeled using a synthetic labeled-projection model, which in conjunction with the image, is projected over a portion of the image of the object profile to derive a histogram. The histogram is normalized and a maximum of a first derivative of the histogram is defined for that position. The position of the labeled-projection model is moved relative to the image, and the process is repeated until a selected portion of the image has been examined. The first derivative of the normalized labeled projection is greatest when a feature of the image and the feature denoted by a specific synthetic label of the labeled-projection model are aligned. The method and apparatus can locate the center of the object with reliability, because use of the labeled-projection model and the histogram minimizes the * effects of image artifacts. Further, the method decreases computational time, and thus, increases performance speed.