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:
Feb. 01, 2000
Filed:
Dec. 01, 1997
Applicant:
Inventors:
Theodore A Camus, Mount Laurel, NJ (US);
Thomas A Chmielewski, Jr, Langhorne, PA (US);
Assignee:
Sensar, Inc., Moorestown, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06K / ; H04N / ; H04N / ;
U.S. Cl.
CPC ...
382117 ; 348370 ; 348701 ;
Abstract
In a method of image subtraction a series of frames of a subject are taken using a video camera The subject is illuminated in a manner so that illumination is alternately on then off for successive fields within the image frame. A single frame is grabbed and an absolute difference between the odd field and the even field within that single image frame is determined. The resulting absolute difference image will represent the subject as illuminated by the system illumination only, and not by any ambient illumination, and can then be used to identify the subject in the image.