is used to capture the stereo images of a body.
These stereoimages of the moving body can be
realtime recorded and restored as high quality
by a recorder, and with a A/D converter inputed
to ¢ micro-computer image processing system-CVGR
sysiem( "Computer Vision for Graph Reading” be
called sth CV2. Lin Zongjian and Lu Jian et al,
1991). Because of stereoimages are got by a CCD
camera, this two images were keep absolutely the
synchronism, that it is benefit to survey for the
moving body . CV2 system has multifunctional
software, that can used to detect the marked
points of the moving body with subpixel accuracy
, to correct geometric distoration of the stereo-
image, to perform 3D-coordinates derivation, and
to analyse for the moving trajactories. This sys-
tem now being used for the study of human body
motion, and obtain the moving trajectories of the
joints on the four limbs, when the human is wal-
king, running, and jumping When a field of view is
2. bm, this system can be to observe a complete
cycie of human gaits. The accuracy of the sur-
veying coordinates can be as point nought five
percent on the first test . This system is desi-
gened as a low cost system
2. SYSTEM COMPONENTS
This system can be composed of a CV2 system
added to a double light-path collecting device
and a image recorder . CV2 is designed as a low
cost system. The main hardware configguartion
of it comprises :
-- À personal computer Super 286
-- À video frame grabber -- WTSM-CV2 board
-- À CCD camera - GOOD LR-1002
-- An image color monitor CTX
-- À double light path collecting device
-- À video image recorder
The systems is shown as Fig. 1.
a ee 7]
CV2
DOUBLE | | CCD S |
LIGHT SOLID Y
PATH | STATE S |
COOLLECT MATRIX "T
DEVICE | | | CAMERA E |
M |
VIDEO | IMAGE
RECORDER MONITOR | |
pris free, d |
| | MICRO COMPUTER IMAGE |
IBM PC —4 INTERFACE BOARD
i 286 & 386 20M hz
Ara as or NISUS d
Fig.1 System Componant
the moving body
double light-paths
collecting device
stereoimage
Fig.2 Double Light Path Structure
2.1 Double Light-path Collecting Device
The structural principle of double light-path
collecting device is shown as Fig. 2. À simple
test device can compose of double-reflecting
mirrors and prism parts, or assemble with imaging
optical-fibers. Obvious in later case light path
of object can be seted flexibly from most favou-
rable observable direction.
2.2 Camera
The camera adopted are of the solid state CCD
type, which allow the best definition in the
images at working speed of 50 places per second.
In addition a image recorder used to save and
restore the image information with high quality.
2.3 Signal Converter-Board A/D and D/A
( A Video Frame Grabber )
It is used for transferring the video signale
acquired by CCD camera to the digitized from and
for the simultaneous display of the image on the
