Page 300 - Digital Analysis of Remotely Sensed Imagery

262 Cha pte r Se v e n

First iteration
8 8
DN of band 2 6 DN of band 2 6 m1 +

4
4
+ m2
2 2
SSE = 93
0 0
0 2 4 6 8 0 2 4 6 8
DN of band 1 DN of band 1
(a) (b)

Second iteration Third iteration
8 8
DN of band 2 6 4 + m1 DN of band 2 6 4 +

+ m1
+ m2
m2
2 2
SSE = 65.52 SSE = 55.75
0 0
0 2 4 6 8 0 2 4 6 8
DN of band 1 DN of band 1
(c) (d)

Fourth and final iteration
8
m2
+
DN of band 2 6 4

m1
2 +
SSE = 20.27
0
0 2 4 6 8
DN of band 1
(e)
FIGURE 7.4 Decision-making process of K-means clustering. (a) Values of the
pixels to be classifi ed in the two spectral bands; (b) clustering results after
each pixel value is assessed against the means of two arbitrarily selected
centers; (c) clustering results after the pixels are reassessed using the
updated cluster centers during the second iteration; (d) clustering results
after the pixels are reassessed using the updated cluster centers during the
third iteration; (e) fi nal clustering results.