US 7,469,060 B2
Infrared face detection and recognition system
Michael E. Bazakos, Bloomington, Minn. (US); Vassilios Morellas, Plymouth, Minn. (US); Andrew Johnson, New Brighton, Minn. (US); and Yunqian Ma, Roseville, Minn. (US)
Assigned to Honeywell International Inc., Morristown, N.J. (US)
Filed on Nov. 12, 2004, as Appl. No. 10/987,368.
Prior Publication US 2006/0104488 A1, May 18, 2006
Int. Cl. G06K 9/34 (2006.01)
U.S. Cl. 382—173 27 Claims
OG exemplary drawing
 
1. A detection system comprising:
a first array of detector pixels having a first field of view;
a second array of detector pixels having the first field of view;
a subtractor connectable to each pixel pair of the first and second arrays; and
a comparator connected to the subtractor; and
wherein:
the first sensing array has a sensitivity to light in a lower portion of a reflective infrared spectrum;
the second sensing array has a sensitivity to light in an upper portion of a reflective infrared spectrum;
a pixel pair includes a first pixel at a location of the first array of detector pixels of the first array which a one-to-one correlation with a second pixel of the pixel pair at a corresponding location of the second array of detector pixels;
the subtractor detects the differences of magnitudes of output signals from the first and second pixels of each pixel pair and output a magnitude difference signal for each pixel pair; and
a comparator compares the magnitude difference signals to a certain threshold value and select the pixel pairs having magnitude difference values on one side of the threshold value.