The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B5. Beijing 2008 
Figure 2. Cover of the Developed System 
The mechanism to take X-Ray images was positioned on the 
roentgen device with the height of 89cm from the film level and 
at least 50% overlapping images were taken. The roentgen 
device creates the image not behind the object (negative image) 
like traditional photogrammetric cameras but it is shown at the 
front of the object (positive image). Due to the positive image, 
camera focal distance cannot be exactly known and anode tube 
source cannot be fixed. It was not possible to measure the base 
distance between two anodes with the desired accuracy. 
Additionally, the mathematical models used in current 
photogrammetric software are based on perspective projection 
rule. Considering all these unknown parameters, the evaluation 
process has been done with Direct Linear Transformation (DLT) 
method. DLT method is used for converting image coordinates 
into object coordinates directly. The most important advantage 
of this system is the fact that it doesn’t require a calibrated 
camera or marked signs. Thus, software with a mathematical 
model based on DLT method has been used (Birgin, 2007). 
In order to transmit the radiographs to digital environment, a 
scanning procedure should be utilized. The radiographs with 
thickness of 120g to 250p are scanned in tiff format with 
300dpi resolution by using a scanner capable of scanning 
negative images in A3 format dimensions, shown in Figure 3 
and Figure 4. 
Figure 3. The Radiograph of the left arm 
Figure 4. The Radiograph of the right arm 
Pixel coordinates of scanned X-Ray films are measured with 
Adobe Photoshop CS2 software. This software takes the upper 
left comer of the screen as the origin. Right and left image 
parameters were found by evaluating the pixel coordinates of 
the retrieved points with DLT method. Than, pixel coordinate 
readings of conjugate points on the bones in right and left films 
were done with Adobe Photoshop CS2 software, Figure 5. 
Figure 5. Left and right hand films with conjugate points 
As a result of the solution of picture parameters with pixel 
coordinates retrieved from the points on the bone, the object 
796