METHOD AND APPARATUS FOR AUTOMATICALLY DETECTING INTRUSION OBJEST INTO VIEW OF IMAGE PICKUP DEVICE

An intruding object detecting method and an intruding object detecting apparatus for judging whether an detected object is an intruding object or not even in the condition that there are shadows of moving objects other than target objects to be detected, such as shaking trees, leaves thereof, etc. An image signal is supplied from an image pickup device; a moving object is extracted from the image signal by a subtraction method; division is made between the image signal and a reference background image signal for every pixel so as to produce a ratio image; a histogram of luminance values (pixel values) is calculated on a part of the ratio image corresponding to the moving object extracted in the extracting step; a pixel value on the part of the ratio image corresponding to the extracted moving object is calculated in ratio representation from the calculated histogram; the calculated pixel value in ratio representation is estimated; and the extracted moving object is judged to be an intruding object or not, on the basis of the estimation of the pixel value in ratio representation. Thus, intruding objects are detected in the field of view to be monitored.