Patent ID: 8369574

Claim:
A person tracking method comprising: a head detecting step of detecting, based on image data that is generated as a result of taking a moving image of a measured space by a camera and represents the moving image generated at a predetermined frame rate, a head on each of a plurality of measured frame images among a plurality of frame images forming the moving image, for each of the measured frame images; a feature-quantity calculation step of calculating, based on the image data, a feature quantity that features a person whose head is detected on each of the measured frame images, for each of the measured frame images and each head; a relevance ratio calculation step of calculating a relevance ratio that represents a degree of agreement between a feature quantity that is on a past measured frame image and belongs to each person whose head is detected on the past measured frame image and a feature quantity that is on a current measured frame image and belongs to each person whose head is detected on the current measured frame image; and a same-person determination step of determining that, among heads detected on the current measured frame image, a head, which is a basis for calculation of a relevance ratio that represents a degree of agreement being equal to or above a first threshold as well as being a maximum degree of agreement, among relevance ratios each between a feature quantity that is on a past measured frame image and belongs to a person having a first head among heads detected on the past measured frame image and each of feature quantities that are on the current measured frame image and belong to respective persons having the respective heads detected on the current measured frame image, is a head of the same person as the person having the first head.