Abstract
Recently, there were various disasters such as Katrina flood, seismic wave in Sumatra, great earthquake in several countries. Inthese disasters, it has become one of the most important rescue activities to detect quickly the victims. If automatic detection of these victims in vast disaster fields is feasible, searching efficiency will be improved spectacularly in comparison with traditional visual search from aircrafts. In this paper, we propose Normalized Difference Human Index (NDHI) in order to extract human images out of various background objects efficiently. For the NDHI, we examine spectral characteristics of the human skin in short wave infrared band, and chose the best wavelengths for its calculation. For marine peril or water disasters, we have conducted experiments with human extraction in and out of the mud water using NDHI. In order to extract objects in the mud water, it is necessary to calculate the threshold operation on the reflectance of 1070nm wavelength as preprocessing of NDHI. In addition, we examined allowable water depth to extract objects for each transparency (intermediate-water, 40, 20, 10cm) . Finally, comparable studies with the conventional thermography measurements were also carried out.
