49
(a)Original data (b)ABIC minimization method
Figure 5. the comparison of histogram before and after applying ABIC minimization
method (1991 July 21)
5-2. Extraction of tidal front
(1) Establishment of classification guideline
Human judgment is necessary for establishing the threshold value from the distribution
pattern of histogram for the single band data used for level slicing, and for extracting the
teachers used for the classification by maximum likelihood method. In the current analysis, it
was difficult to establish the classification standard even though the reference guideline was
available, such as tidal front location confirmed by sea truth. Therefore, it is considered to be
difficult to apply the human judgment for establishment of threshold values and extraction of
teachers in constructing the practical model.
(2) Comparison by the number of band
The water block classification by single and multi-band clustering some times produced
different results (Fig.6). However, the borderlines of water blocks close to the sea truth were
extracted in both results. As far as seen from the comparisons, it was shown that increase of
band number does not necessarily contribute to the enhancement of accuracy of water block
classification.
Figure 6.
(a)Single-band
Comparison of classification result by
(b)Multi-band
single and multi-band(1992
May 25)