Human detection and localization at indoor environment by home robot

The system introduced in the paper estimates the 3D position of a human´s head and face by using the depth from focus method. First the system locates the human´s head and face by using motion detection, Hough transform and a statistical color model. Then by changing pan, tilt and zoom of camera we put the face in the center of the camera´s field of view. Then we use information from focusing the ring of an autofocus camera to measure the distance between the human face and the camera. By having information about the absolute position of the camera and its pan and tilt angles we can compute the absolute position of the person in the room. In the case of a person with small motions, this system measures distance with less than a 10 cm error. The measurable distance range is from 90 cm up to 340 cm