Patent ID: 6697104
Filing Date: 2004-02-24
Classification: G06K,G07C,G08B

Abstract:
A method for detecting and counting persons traversing an area being monitored comprising:initialization of at least one end unit forming part of a video imaging system, said end unit having at least one camera installed therein, said camera producing images within the field of view of the camera of at least part of the area being monitored, said end unit comprising at least a non-volatile memory unit and a working memory unit, the non-volatile data memory unit comprising a plurality of counters; digitizing said images and storing said digitized images in at least one of said non-volatile memory unit and a working memory unit; detecting objects of potential persons from said digitized images; comparing the digitized images of objects detected in the area being monitored with digitized images stored in the working memory unit to determine whether the detected object is a new figure that has entered the area being monitored or whether the detected object is a known figure, that has remained within the area being monitored and to determine that a figure which was not detected has left the area being monitored; and incrementing at least one of said plurality of counters with an indication of the number of persons that have passed through the area being monitored, wherein said initialization step comprises the step of determining the optimum pixel scale (Pscale) required for processing in accordance with the formula: Pscale=HÃ—WccdWpixelÃ—Fccd,where&it;:=H=Height;Wccd=width&it;â€ƒ&it;of&it;â€ƒ&it;the&it;â€ƒ&it;camera&it;â€ƒ&it;sensor;Wpixel=width&it;â€ƒ&it;of&it;â€ƒ&it;the&it;â€ƒ&it;FOV&it;â€ƒ&it;in&it;â€ƒ&it;pixel&it;â€ƒ&it;units;Fccd=focal&it;â€ƒ&it;length&it;â€ƒ&it;of&it;â€ƒ&it;the&it;â€ƒ&it;camera.