International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B5. Istanbul 2004
+Mirrors
Both axes for laser range finder and amateur digital camera
are adjusted by two mirrors (mirror and half mirror).
+Camera
OLYMPUS C-3040 (3.14 mega pixels)
+ Laser profiler
Leica LDS-1 (accuracy is =3mm to 40m)
+ PC
Pentium II 850Hz
Laser
range
finder and
amateur digital
can
1era are
controlled by personal computer, and captured image data
and measured distance data are recorded on hard disk
(mounted on 10GB).
+ Monitor
6.4-inch display is used as a finder and PC monitor.
the high-
designed
nt digital
ind these
| camera,
tem is its
his paper
ordinate.
| absolute
erformed
for ideal
ge Based
ed by the
ability to
aramelers
previous
he IBIM,
System
, amateur
outer and
stem, and
9) rotate in
ince from
Id can be
evice with
and 3D
system are
Figure 1. Appearance of the IBIM
3. CAMERA CALIBRATION
In order to perform camera calibration, at least 6 space
distances for the points, which show feature on object field
from the center of a camera, have to be measured by laser
profiler. These feature points are defined as temporal GCP in
this paper. Then, 36 unknown parameters such as exterior
orientation parameters for both camera {(Xors Yors Zots O1, Pi,
Kr), GXog, Yon. Zor Or, Pr Kr)}, interior orientation parameters
U (focal length), xy v, (principal points), a;, az, (scale factor),
k; (lens distortion)) and 3D coordinates for the 6 temporal
GCPs should be calculated. However, X or Y-axis and 2 points,
which have the same height value or height values for 2 points,
are required to prevent rotations. Therefore, origin point and the
point, which define the X-axis direction, are selected. 3D
coordinates for the origin point and the point are assumed (0, 0,
0) and (X, 0, 0) respectively. As a result, 30 parameters
become unknowns, and these unknown parameters are
calculated by collinearity condition and space distances
simultaneously. Detail calibration procedures are as follows.
Figure 3 shows the concept of measurement by the IBIM.
(Wg, Pr Kp
X (Xon. Yan. Zor)
Figure 3. Concept of Measurement by the IBIM
vn Measurement... — ^ eese nospiteen Control cer
: Part : :
virror Control i Mother Board
Laser ES odd
Range Finder Li. . » | HDD | | GPL | =
: Distance | 5
Neassenionateususnasaegiasetnsvssaaeseust Data | M EMO VY | =
+
e
- d M---------- = Data
iL Digital |
i Camera | us Video
Half : Image Capture Battery
Mirror ; Data Dewic
k eereeu iere euenit Image Ac quiring Parte eredi
Figure 2. Configuration of the IBIM
