DYNAMIC ANALYSIS OF HUMAN MOTION USING SEQUENTIAL IMAGES
OF VIDEO THEODOLITE
Hirofumi CHIKATSU, Tetsuji ANAI, Hideharu YANAGI
Department of Civil Engineering, Tokyo Denki University
Hatoyama, Saitama, 350-03, Japan.
Shunji MURAI
Institute of Industrial Science, University of Tokyo
22-1, Roppongi 7 Chome, Minato-ku, Tokyo, 106, Japan.
Commission V, Working Group 5
KEY WORDS; Video theodolite, Image, Calibration, Matching, Dynamic analysis, Human motion
ABSTRACT
Video image sequences often give important information about dynamics of human motion in the field of sports training or
rehabilitation. For understanding of the dynamics of human motion from video image sequences, there are two
complicated subjects which have to be resolved. One is how to estimate the photogrammetric camera orientation
parameters on a moving camera. The second is image processing, for example, automated recognition of human feature
points such as the head, elbows or knees.
This paper describes an application of a video theodolite system and image processing procedure with regard to the
above two issues for dynamic analysis of human motion.
1. INTRODUCTION
Generally, a dynamic analysis of human motion has been
performed under a condition that camera position and
rotation are fixed and some markers are fitted on the
body.
Therefore, it is possible to calibrate the camera
parameters in advance. Also, automated recognition of
some human feature points such as the head, elbow or
knees is possible.
In order to understand a dynamic analysis of the most
natural human motion, limitation of the camera and any
marker on the body should be removed. For this ideal
dynamic analysis, however, camera orientation
parameters should be acquired in real time while recording
a moving object. Furthermore, automated recognition of
some human feature points should be performed.
The effectiveness of the video theodolite system for
dynamic analysis of human motion has been indicated by
the authors(Chikatsu and Murai,1995). This paper
describes the dynamic analysis of human motion using
sequential images which are taken by video theodolite.
Also, image processing techniques are described.
2. VIDEO THEODOLITE SYSTEM
In order to acquire the camera rotation parameters in real
time, a CCD camera was mounted on top of a theodolite as
camera axis x,y,z coincide with theodolite axis
X(horizontal axis), Y(vertical axis) and Z(collimation axis).
Then, wand ¢ were defined as thevertical and horizontal
angles respectively. x is assumed to be 0 degrees as the
theodolite is levelled. This concept was first published in
(Huang and Harley,1989).
88
With this motive, the authors have been concentrating on
developing the video theodolite system consisting of a
CCD camera, a theodolite and a video recorder where the
camera rotation parameters can be determined in real time
while recording a moving object. The current values of the
rotation parameters were then continuously
superimposed on the image frames and thus recorded as
a part of the image data (Chikatsu and Murai,1994).
Last year, SOKKIA corporation developed a motorized
video theodolite (MET2NV, Figure 1) in association with
the authors. MET2NV were developed based on
MONMOS(the first order total station), and main feature
points consist of two CCD color cameras. The current
values of the rotation angles( vertical and horizontal) and
distance were then continuously superimposed on the
image frames. CCD 1 is the upper one in figure 1 and is
used for precise pointing to the target through the
monitor, and CCD 2 is the lower one and is used as a
finder.
Figure 1. Video theodolite (MET2NV)
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996
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