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:
Jan. 25, 2011
Filed:
Jan. 11, 2006
Yun-ting Lin, White Plains, NY (US);
Tomas Brodsky, Croton on Hudson, NY (US);
Mi-suen Lee, New York, NY (US);
Yun-Ting Lin, White Plains, NY (US);
Tomas Brodsky, Croton on Hudson, NY (US);
Mi-Suen Lee, New York, NY (US);
Honeywell International Inc., Morristown, NJ (US);
Abstract
To calibrate images from an overhead camera, two equal-length reference lines at different heights relative to the floor plane are imaged. By comparing the resultant image-width of each of these lines in the view provided by the camera, the effective focal point of the camera is determined. In a preferred embodiment, a doorframe is used to provide equal-length lines at different heights parallel to the floor. The threshold of the doorway at the floor plane is used as a reference plane, and a parallel calibration line at a known/measured height in the doorway is defined. The image produced by a vertically oriented camera of these two equal length lines will show a longer line at the elevated position, the different widths of the images of these lines being dependent upon the camera's effective focal point. From these two projections of the equal-length lines at different heights, the camera's focal point distance from the reference floor plane is determined.