Barsi, Arpad
The first experiment was the usual classification with the
original image bands. Then PCA-analyzed and transformed
bands were processed. The results of these classifications are
very similar as Figure 15 demonstrates. The map is very
smooth; it contains too much urban pixels. The redundancy
could be reduced in this way, which accelerated the design and
training.
The principal component analysis and Karhunen-Loeve
transformation are nice tools for data reduction.
Considering pixels’ neighborhood information just the opposite
results have arisen. The thematic map is “noisy”, disturbing
pixel differences could be noticed. The design is much slower
and harder, than the original version. The application of the
“raw” direct and indirect neighborhood has therefore not too
much sense.
The main result of current project is the combination of the
neighborhood information and the PCA data compression
technique. The resulting thematic map has enough details, but is
generalized. The output of this last method is high quality,
esthetic thematic map. The 4- or 8-neighborhood are differing in
the designing, training and processing time; the map quality is
very similar. 8-neighborhood map has more contrast (“edge
detected”), but the cost-benefit analysis would prefer the
simpler and faster 4-neighbor solution.
Current research work is just documented, isn’t at the final
stage. Future works are planned in the application of PCA after
the training set preparation, in the extension of neighborhood
and evaluating information content series.
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