TOWARDS A HIGHER LEVEL OF AUTOMATION 
FOR SofiPlotter™ 
Yan Lue, Senior Photogrammetric Engineer 
Vision International 
A division of Autometric, Inc. 
502 Earth City Expressway, Suite 203 
Earth City, MO 63045, USA 
lue(@stl.autometric.com 
Commission III, Theory and Algorithms 
KEY WORDS:  Photogrammetry, Automation, Matching, Interior Orientation, Feature extraction, Tie Points selection 
ABSTRACT: 
In this paper we present the efforts on two important aspects of automation for the digital photogrammetry system: Automatic 
Interior Orientation (470) and Automatic Tie Point Selection (A47PS). The latter one covers the traditional point selection, transfer 
and mensuration. Both modules are available in the SoftPlotter™ softcopy photogrammetric workstation from Vision International. 
A fully automatic .4/0 module based on template matching, together with LSM techniques suitable for most commercially available 
aerial cameras, has being running on many SoftPlotter™ for over a year. A success rate of one hundred percent for fiducial 
recognition with very high accuracy was achieved on several hundred test frames. Thousands of frames have been processed with 
AIO by SoftPlotter users with satisfactory results. The processing time averages only a few seconds per frame with eight fiducials. 
Another fully automatic module A7PS is based on a series of sophisticated image matching algorithms and strategies. The beta 
version has been applied to some practical projects. The A7PS results for a variety of strips covering image scale from 1:3400 to 
45000 with all kinds of different textures, including urban area with strong distortion, forest, mountain, wetland, desert, rivers, 
lakes etc., are very promising. The feedback from the real world is very positive too. The averaging success rate was about 85 
percent. The processing time was less than a half minute per frame with points on nine standard positions. 
0. INTRODUCTION 
Digital photogrammetry (DP) is coming out from its research 
and development period and into day-to-day practice. 
Commercial photogrammetric companies are rapidly turning to 
digital photogrammetric workstations and systems to meet 
production requirements. Traditionally, the most time- 
consuming and labor-intensive task is the mensuration of the 
all kinds of points, such as fiducial marks, ground control 
points, tie points. Somewhat surprisingly, however, while 
most commercially available digital photogrammetric systems 
have provided automatic photogrammetric data collection and 
product generation for DEM and orthophoto for quite a while, 
the most fundamental operations of photogrammetric 
processing like interior orientation, tie points selection and 
mensuration needed by aerial triangulation (AT) are still often 
performed manually as on an analogue or analytical plotter. 
In this paper we present our efforts on two important aspects 
of automation for the digital photogrammetry system: 
automatic interior orientation (4/0) and tie point selection 
(ATPS). The first part gives a brief description on the basic 
concepts and technical strategies and then introduces some 
results on thousands of aerial photos taken by eight popular 
aerial cameras (Wild RC8, RC10, RC20, RC30, Jena LMK 
1000, 2000, Zeiss RMK TOP 15, RMK A 15/23, 30/23) (Lue, 
1995). The second part describes methods and strategies for 
ATPS procedure, which shares a similar philosophy and 
methodology but uses more sophisticated strategies and 
478 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B3. Vienna 1996 
organization. A summary about the ATPS results on 16 data 
sets with different image scales, different scanning resolutions 
and all kinds of different textures, including urban area with 
strong distortion, forest, mountain, wetland, desert, rivers, 
lakes etc. is also provided. 
Some technical and practical points is discussed in the 
successive section, then a conclusion is drawn in the last part 
of the paper. 
1. FULLY OPERATIONAL AUTOMATIC 
INTERIOR ORIENTATION (AIO) 
In photogrammetric processing image measurements of all 
points, no matter if they are tie, ground control, feature or 
terrain elevation points must be reduced to the camera system 
central perspective coordinates. For the DP processing a 
hardcopy film is arbitrarily put on a scanner for digitizing. A 
set of transformation parameters is therefore needed to derive 
the film coordinates from the scanning ones or vice versa. The 
tasks of recognizing and measuring fiducials for deriving the 
transformation parameters between the scanned image and 
camera coordinate systems comprise the two basic tasks of 
interior orientation. As well known, the latter one has been. 
well established. The automation of the interior orientation 
needs to concentrate primarily only on the former 
   
   
    
   
  
  
  
   
    
    
    
  
  
  
  
   
    
     
    
   
   
    
     
      
   
    
  
    
      
     
     
     
   
   
   
    
      
    
   
    
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