Earthquake Engineering Research - HKU Libraries - The University ...

kindergarten, library, and dwellings were established at the other area where these official
buildings located before the disaster, because all these official buildings were collapsed for the
earthquake. The reconstruction of original area where these facilities were located before the
disaster is still on the way. Continuous monitoring on both temporary town and reconstruction
area is conducted using five CCD camera sets. Observations were started from April 19, 2001.
The location and the images of CCD camera systems will be shown in Fig.4.
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CCD1 CCD2 CCD3 CCD4
Fig. 4 Monitoring at Chungliao, Taiwan
CCD5
3. IMAGE PROCESSING
3.1 Processing procedure
These images are useful to understand present status and sequential images are useful to
understand a physical disaster process by intuition. However, amount of data is huge and the
development of automated data processing method is necessary to get the numerical data on the
physical recovery. And to make a comparative study, the standardized procedure is
indispensable. The method to get the time series of the physical recovery from a series of
observed images will be discussed in this chapter. We will define the amount of buildings as the
physical recovery degree from disaster.
The observed data contains the noises such as 1) moving objects such as cars, people, 2) the
shadow of buildings from the viewpoint, and weather such as rain. So removing these noises is
the first step for image processing. In this paper, the basic procedure to get physical recovery
degree using observed data is discussed. On the other hand, moving objects means physical
recovery. This is a very important element to understand recovery process.
3.2 Removing the noises
3.2.1 Removing moving objects
The method to get averaged image of observed images was used to remove moving objects