Hongo, Kenji 
  
2.3 
Processing flow 
Processing flow of the system is similar to one of a conventional method by analog/analytical photogrammetry. Figure 
1 shows the flow of the standard processing of the system. 
(1) Image acquisition by digital still cameras 
It takes a long time and a high cost to take stereo images all over the object with spatial resolution requested for 
restoration purpose. Therefore we adopted a two-stage image acquisition method for saving time and cost. At the 
first stage, a pair of stereo images covering the whole object is acquired. We call this pair of images index images. 
Index images are used for extraction of DEM used at generation of digital ortho images, and for orientation of 
detailed images that are acquired at the second stage. Spatial resolution of index images is worse than requested 
resolution of a digital ortho-image used in the restoration information management subsystem, but is sufficient for 
both DEM extraction and orientation of detailed images. At the second stage, detailed images are taken with spatial 
resolution requested for restoration purpose. It is not necessary to take a stereo pair image or to cover all over the 
object. A detailed image is taken of an interesting part of the object, and it is referenced to an ortho mosaic image of 
index images. Both index and detailed images are acquired by a digital still camera that is controlled by a note-type 
PC. 
(2) Orientation of images 
Positions of control points and pass points on images are measured on a PC display. Orientation of index images is 
executed by the bundle adjustment. A scale such as a staff in leveling taken in an image gives a scale of the model. 
A mosaic orth-image of index images is utilized as a base map at orientation of each detailed image. 
(3) Generation of mosaic ortho-images 
DEM for generating ortho-images of index and detailed images are made from index images. Extraction of DEM is 
executed automatically in principal. All of acquired index and detailed images are transformed orthographically. 
Finally each ortho-image is connected with the other, and mosaic ortho images of index images and detailed images 
are generated. After this we call mosaic ortho images of index images and detailed images mosaic index image and 
mosaic detailed image respectively. 
(4) Mapping of damaged area and restored area on a mosaic detailed image 
A restoration research maps current status of the object on a mosaic detailed image. The extent of a damage such as 
mold, exfoliation, scratch, peel off, hole and salt damage are mapped, and supplementary information is stored in a 
DB with reference to the position. A restoration research also indicates the extent of a restored area, and inputs 
supplementary information into in the DB with reference to the position. 
(5) Retrieval of information about damage or restoration 
A restoration research can retrieve any information about damage status and/or restoration histories of the object, 
and obtain retrieval results in the form of tables, figures and images. 
  
  
    
  
  
   
   
Index 
mosaic 
ortho-images 
Generation of 
index mosaic 
ortho-images 
Acquisition of ^ 
Orientation of EN 
index images 
index images 
  
  
  
  
  
  
  
  
  
  
Y 
  
  
  
  
  
  
  
  
  
  
  
  
  
   
  
  
  
   
  
   
  
     
  
  
  
  
   
Figure 1. Flow of the standard processing 
   
  
   
  
  
: : ; Generation of Detailed 
Acquisition of N Orientation of ==") detailed mosaie mosaic 
detailed images detailed images Grtho-qmases ortho-images 
Information Retrieval of Restoration Mapping of 
about damage information about Comme damages area 
or restoration damage/restoration and restored area 
  
  
  
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000.