| keep 
rnt ion 
racks 
ately. 
s and 
; to 
which 
asure 
  
  
995 
  
355 
  
Line Camera Uint 
    
  
   
Camera incline angle 
Camera View angle 
Railway 
== 
J Spring 
1 1 
  
  
Cut View ( from front side ) Side View 
  
  
FIELD EQUIPMENTS. | . Motor Car 
Digital Data Recorder 1 Fi 
Camera and Light Frame di Lt bl 
  
  
  
  
  
  
  
  
Railway 
tient Le ir | S * AC Power Supply 
Camera Line Camera Driver 
  
  
Figure 2. Image of the line camera setting 
2. THE SYSTEM OUTLINE 
The inspecting system , now under developing , is 
consisted on a line sensor camera for capturing 
the successive images , a Digital Data Recorder 
(DDR) that can record a large image data , and an 
engineering work station(EWS) which is processing 
that image data (Fig. 2 & Fig. 3). 
At the filed , these units ( a line sensor camera 
and digital data recorder ) are loaded on the 
trolley and pulled by the engine which is called 
the Motor Car ,and the image data is recorded in 
real time to the data tape in the Digital Data 
Recorder Those data are sent to the 
engineering work station ( SUN : Spark 
Station 2 ) for image processing later in the 
laboratory . 
This system can takes the successive images from 
running car with a line sensor camera , and record 
to a data tape as a digital image data , and it is 
possible to process those data by a computer 
without an analog digital conversion. 
One of most different part between a Video Camera 
(an area sensor camera ) and a Line Camera is , a 
Video camera records a image of area , on the 
other hand , a Line Camera records a image of 
line , so if the camera would not move , it is 
€ 
scanning the same line. 
For the case of using a Video camera ( an area 
sensor camera ) and a Video Cassette Recorder , it 
can record 30 frames ( picture of area images 
NTSC standard ) per one second. 
The problem of this method is , the same subject 
will be appeared on different frame like as 
overlapping . 
Figure 4 and Figure 5 show two images of 
continuous frames of Video data at TIME 1 and 
TIME 2. 
Wrok Statio 
    
  
INTERFACE 
   
| —— | 
o ÁÓ ess |: 
| — om | | 
| m | Dp 
Data Tape ‘ - 
(Recorded in the field) t 
(SUN Sparc2) 
Data is transfered from DDR to Workstation 
in 8 Bit parallel with custom interface 
  
  
Figure 3. Line Camera system 
  
  
XPOSITON 1» «POSITION 2» 
  
  
  
Figure 4. Difference of image size on the area 
image sensor 
  
Time line J 
( camera position movement ) 
LH A 
  
  
  
  
  
  
  
  
  
  
  
  
Spring 
lr Image at T2 
Ti N 
Image at T1 
  
  
  
Figure 5. Continuous frame pictures of 
Video Camera at T1 and T2 
IAPRS, Vol. 30, Part 5W1, ISPRS Intercommission Workshop “From Pixels to Sequences’, Zurich, March 22-24 1995