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:
May. 29, 2001
Filed:
Mar. 14, 1995
Apparatus and method for determining the location and orientation of a reference feature in an image
David Michael, Newton, MA (US);
Arman Garakani, Cambridge, MA (US);
Cognex Corporation, Natick, MA (US);
Abstract
A method and apparatus for determining the location and orientation of a reference feature in an image is provided. At train-time, a template image is created for use during the run-time phase. At run-time, a reference feature is located by first determining the principal angle of the reference feature. In a preferred embodiment, the principal angle &thgr; of the reference feature is found by partitioning the reference feature into a plurality of regions, projecting each of the regions at 0°, and performing template matching with a template image to determine the position of a plurality of points along a principal axis of the reference feature. Then, either an equation of a “best fit” line can be calculated and solved simultaneously with an equation of a horizontal reference line, or the reference feature image can be projected at the angle of the “best fit” line to obtain a one-dimensional reference image which can be matched to the one-dimensional template image to find the relative displacement between them that maximizes a match-metric value. The invention is particularly useful for determining the location and orientation of reference feature images that have been degraded in some way. The invention provides substantial immunity to such image degradation by comprehensively exploiting image information derived from the entire image of the reference feature.