Human Motion Tracking And Experimental Research

Human motion tracking and analysis has been receiving increasing attention from researchers in the fields of image processing and computer vision during the past few years. It has a lot of applications in smart surveillance system, virtual reality, advanced user interface, motion analysis and model-based coding, etc. The procedure of the human motion tracking and analysis from a sequence of images involves three main stages: (1) human body segmentation in a complex scene; (2) human motion tracking and body structure reconstruction; (3) motion analysis and action recognition. As the base of the human action recognition and understanding, human motion tracking and body structure re-construction is the key of the whole procedure. Action recognition is the highest level of motion analysis, but now it is far from application. The researching work mainly focus on the first stage and second stage. This paper proposes several methods of tracking human motion from a single view. The precise correspondence between the human region of the image and the real human body is established through analyzing the feature extracted from the human body region of the image sequence, the motion parameters are obtained, ultimately the sequence of human motion is recovered.The image sequence is acquired by a single camera. Firstly, the human region is extracted from the image by the background subtraction, then model-based and none model-based method are applied to track human motion from body parts to whole body. In this paper, two parts of the body leg and head are tracked. The lower limb is tracked using geometric characteristics, the original image sequence is first transformed to the distance image sequence, and then the four joints of the leg are tracked on the distance image sequence. Based on visual perception, the head is tracked using color information of face and matching is proceeded from coarse to fine matching, fuzzy pattern recognition is also applied during fine matching. In the tracking of whole body, a model is described according to the body shape. Using this model, simple and complicated movements such as walking and throwing motion are labeled, and the 2-D coordinates of joints can be got. At last, the 3-D positions of joints are obtained by the model of perspective projection combined with the relationship among joints, and human motion is recovered by 3-D stick model.The experimental results from body parts movement to whole body movement are given and the tracking methods are compared with existing methods. The experimental results show that the matching method using distance image in leg movement, using key frames in walking tracking, and the matching between the model and first frame based on head location are the contributions to the human movement research. At last the further suggestions for the improvement of the system are discussed.