Hongo, Kenji 
  
2.4.3 Image acquisition subsystem 
Hardware of the image acquisition subsystem consists of a note-type PC, digital still cameras with more than mega 
pixels, lighting equipment and scales such as a staff in leveling as shown in Figure 2. 
The system can make an image acquisition plan according to the size of the object and the limitation of space in front of 
the object. Whether a research accepts the proposed image acquisition plan or not, images are acquired by a digital still 
camera controlled by a note-type PC. An aperture of lens and a shutter speed of a digital still camera can be controlled 
by a PC, and a PC can release the shutter of the camera. Image data are transmitted to the PC as soon as taking the 
image, and the PC registers the transmitted image with information about the image taking condition in the DB of the 
system. Control of a digital still camera by a PC enables an amateur photographer to obtain proper images easily 
because quality of a taken image can be confirmed in real time. A scale taken in an image gives a scale standard. 
Figure 4 shows a scene of image acquisition by a digital still camera controlled by a note-type PC. 
  
Figure 4. Image acquisition ! 
2.4.4 Ortho-image generation subsystem 
The ortho-image generation subsystem needs only a PC at the minimum. This subsystem usually runs on a PC not at a 
heritage site but in an office. 
Software of this subsystem is based on digital photogrammetry and image processing technologies. Images acquired by 
the image acquisition subsystem are transferred into this subsystem. Then this subsystem creates an ortho-image of each 
image and a mosaic image by connecting the ortho-images. This subsystem shows a pair of index images at processing 
of index images, or a mosaic index image and a detailed image at processing of detailed image on a PC display, and a 
user indicates some control points and/or pass points in both images on the display. This is the major task for a user to 
do in this subsystem. Orientation of images is performed by the bundle adjustment with geometric constraints. A mosaic 
index image and a mosaic detailed image are created automatically and registered in the DB of the system. 
Figure 5 shows a screen for measuring image coordinates of control points. Measurement of image coordinates of 
control points is the major manual operation of this subsystem. 
2.4.5 Restoration information management subsystem 
The restoration information management subsystem needs only a PC at the minimum. A color printer is very useful in 
this subsystem. This subsystem usually runs on a PC not at a heritage site but in an office. 
Software of this subsystem is based on GIS technology. This subsystem can manage information about the current 
damage status and restoration records of the object. The mosaic detailed image created by the ortho-image generation 
subsystem is used as a background image in this subsystem. A user inputs some information about current status of the 
object or restoration records of the object on the mosaic detailed image displayed on the PC screen. Information stored 
in the DB of the system can be retrieved complying with a user request. For instance a restoration researcher can obtain 
  
376 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000.