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:
Sep. 29, 1992
Filed:
Sep. 11, 1990
George C Lee, Williamsville, NY (US);
Xianyi Sun, Beijing, TW;
The Research Foundation of State Univ. of N.Y., Albany, NY (US);
Abstract
A visual image comparison method is provided, including the steps of: obtaining a first digital representation of a first visual image, where the first digital representation comprises a first plurality of pixels, and each pixel has a gray scale indicative of light intensity; obtaining a second digital representation of a second visual image, where the second digital representation comprises a second plurality of pixels, and each pixel has a gray scale indicative of light intensity; and selectively making a first predetermined number of comparisons of corresponding pixels from the first and second digital representations to determine whether a difference in ambient light intensity exists between the first and second visual images, and, selectively making a second predetermined number of comparisons of corresponding pixels from the first and second digital representations if and only if no difference in ambient light intensity exists between the first and second visual images, and indicating an alarm condition when a percentage of the second predetermined number of comparisons result in pixels having a difference in gray scale of a predetermined amount. Apparatus is also described for the purpose of implementing the method.