ix 4700Z (FUJI FILM) 
  
  
  
  
  
)C-3 (RICOH) 
  
  
  
  
S560 (Kodak) 
l'echnology 
olation) 
| Pixel) 
[ega Pixel) 
y (7.07M ega Pixel) 
  
  
IGITAL 
900Z 
Pix 700 
Pix 4700Z 
[100V 
00ZOOM 
)30200M 
3 
-] 
X1 
Pix S1 Pro 
560 
  
were performed by the bundle adjustment using 9 control 
points. After the camera calibration, accuracy was estimated 
using R.M.S.E. for 33 check points. 
2.2 Evaluation of Lens Distortion 
In order to estimate lens distortion for digital cameras, three 
different lens distortion models were investigated. The model 1 
and model 2 consider only radial symmetric distortion, and 
model 3 considers both radial and tangential distortion (Fryer, 
1986). 
It can be said from the results that lens distortion for the 
amateur cameras can be corrected sufficiently using radial 
polynomial 3rd degree model as usual. 
2.3 Evaluation Accuracy for Number of Pixels 
In order to investigate variation of accuracy by increment of 
resolution, relationship between number of pixels for each 
camera and R.M.S.E. for check points which calculated using 
radial polynomial 3rd degree model were investigated. Figure 2 
shows relationship between number of pixels and accuracy. It 
may be seen from Figure 3 that the accuracy of more than 3 
million digital cameras are hardly varied. 
2.4 Evaluation of Image Quality 
Figure 4 shows the magnified circle target which were taken by 
DC-3 (0.31M), CP-900Z (3.34 M) and DCS560 (6.10M). 
Obviously, difference of image quality between 0.31M and 
3.34M pixels can be found. Nevertheless, it can't be found 
significant difference between 3.34 and 6.10M pixels. 
Consequently, it is concluded that 3 million amateur cameras 
will supply the place of the professional digital cameras. 
  
0.31M pixels 3.34M pixels 6.10M pixels 
Figure 4 Image quality and number of pixels 
3. LOW-COST PHOTOGRAMMETRIC SYSTEM 
Generally, ground control points (GCP) or actual distance in 
object field are needed for camera calibration. However, these 
conditions in object field should be removed in digital 
photogrammetry using amateur cameras. In order to resolve 
these issues, laser range finder (Leica, DISTO pro) was 
combined with amateur camera (CP-900Z) so that scale factor 
in relative orientation can obtain. Furthermore, ® and can be 
estimated as 0 degree as a advantage since the system is set on 
the leveling stand for theodolites. Figure 5 shows appearance of 
the low-cost photogrammetric system. Actual 3D coordinates 
can be calculated via absolute orientation using altitude or 
distance after relative orientation using interior orientation 
parameters which were previously acquired with test model. 
In order to evaluate of this system, the center of each black 
circle point on the test target (Figure 6) were measured by total 
station and accuracy for the following 4 cases were estimated 
using R.M.S.E. for 42 black circle points on the test target. 
The shapes of each point should be considered since accuracy 
depends on the pointing accuracy of image coordinates. 
Nevertheless, in order to reduce labor, time for measuring 
coordinate and automatic data acquisition, circle target was 
adopted and an image coordinates for each point were given as 
a center of area gravity by image processing. 
  
Figure 5 Low-Ccst Photogrammetric System 
In order to cover wide area, wideangle conversion lens 
(Raynox, CPR-6600) was fitted to a lens of the digital 
camera (CP-900Z). 
  
  
Figure 6 Test Target 
e Altitude is given (Case 1): Altitude 3.421m (left image) and 
3.429m (right image) were measured respectively by laser 
range finder, and original point and direction of X axis were 
given on the image. 
e Distance is given (Case 2): Stereo image are the same with 
the above, but only distance in the objects fields was 
measured, and original point and direction of X axis were 
given on the image. 
e Distance and two height points are given (Case 3): 
Conversion stereo image were taken without the system as 
the third case under the assumption that parallel stereo image 
often can't take. Distance in the objects fields was measured 
and original point and direction of X axis were given on the 
image. But, in order to control an influence of rotations, at 
least two height points are needed. 
—339—