Algorithm for counting the number of persons using IR image processing

For security purpose, the counter for the number of persons who pass a door is required. Several kinds of counters, such as the automatic wickets of stations or the rotation-bar entrances of museums, parks have developed. But these are in contact with persons or obstruct the paths because non-contact type of those call not count correctly. We propose an algorithm for non-contact counting of the number of persons without the recognition of each individuals. The algorithm is for infrared (IR) images and the images are processed in a personal computer with a frame-memory board. The images were replayed with a video deck in off-line manner and the algorithm exhibits to give the accuracy of 90%