SINGLE CCD CAMERA BASED THREE DIMESIONAL MEASUREMENT
SYSTEM FOR MOVING OBJECT
Lu Jian , Lin Zongjian ‚Pan Dongchao
Department of Photogrammetry and Remote Sensing
Wuhan Technical University of Surveying & Mapping
39 Loyu Road, Wuhan 430070,
ISPRS Commission V
ABSTRACT
CHINA
This paper presents a sub-realtime 3-D coordinate measuring system with single CCD camera for
a moving body .The signalised points of a moving body can be realtime-tracked and realtime
-recorded in 50 times per second . A double light-paths collecting device which is placed in
front of a CCD camera ,is used to capture the stereoscopic image of a moving body. For
3-D measurément, the steroescopic pair can absolutely keep the synchronism of double-
images . The double light-paths collecting device can be a simple double-reflecting mirrors
orimaging optical-fiber device. The videoimage signal digitized with a A/D converter and input a
micro-computer image processing system, which is used for the determination of feature points
and the derivation of coordinated .A 3-D closed-range testfield is used for the detemination of
the interior and exterior orientation of the camera and of parameters of lens distoration. The
signalesed points on moving body are detected by automatic match algorithm with subpixle accu-
racy .This system has been using for the study of human gaits .Using simple reflecting-mirrors
device in 6 meters view field, the accuracy
percent,
of the first test can be as point nought five
KEY WORDS: Computer Vision, Pattern Recognition, Image Match, Stereo-Photographing, CD Camera,
Sub-Pixel Detect, DLT-Direct Linear Transformation.
1. INTRODUCTION
The recent developments in the fields of pattern
recognition and computer vision open a new way
to measure and analysis moving objects. The
present-day realtime photogrammetry method nor-
mal'y adopts two and more TV or CCD cameras to
pertorm stereophotography, and then the 3D-coor-
dinates of the object points are derived by
image matching But this method has not yet popu-
larized because of the complexity of the deriva-
tion by image match and mass amount of data
to be processed. In practice, we can simplify this
method according as the requirement for a analy-
tical task.For example, for simplifiesthe mast
complex steps of image matching, the relevant
characteristic points an the body are marked by
surtable pattern, and illuminated by fiashing
light sources, whose direction of emission is
coaxial to TV cameras and the realtime detecting
and recording this signing points, The trajecto-
ries of little points describe the movement of
the body.
Since seventies , the research of the motion
analysis system has been very quick developed
along with advanced of the computer technic. So
far as based technic method , as stated above ,
they are based on the theory of the stereo-pho-
togrammetry , which extracted 3D-coordination of
the feature points from dynamic images of the
moving body. There are typical systems , example
SELSPOT system of Swedish (Woltring and Marsolais
, 1980), VICON syatem of England Okford Company
(Jarrett et al, 1976), Elite system of Italy
(Ferrigno and Pedotti, 1986) , and Coda system
(Mitchelson, 1975) . The new commercial product
uninterruptelly push out. These systems have the
high-grade headware, and the function of the
software has been improvedstep by step. But they
are expensive , therefore not yet popularized in
the developing countrys.
In this paper a motion analysis system which has
a simpler compose and a completer function than
abovementioned system will be described. In this
system a CCD state matrix camera , front which
attached a double light-paths collecting device,
