Figure 7.4 - Watershed oversegmentation
For image segmentation, the watershed is usually applied on a gradient image. As real digitized images present many regional minima in their gradients, this typically results in a large number of catchment basins. This characteristic, called “watershed oversegmentation,” is illustrated in Fig. 7.4: (a) the morphological gradient, (b) regional minima, and (c) catchment basins of the watershed transform originating from all regional minima.
1 import ia870 as MT 2 import numpy as np 3 4 f = np.transpose(adreadgray('beef.tif')) 5 6 g1 = MT.iagradm(MT.iaclose(f)) 7 adshow(MT.iapad(MT.ianeg(g1)), '(a)') 8 9 g2 = MT.iaregmin(g1) 10 adshow(MT.ianeg(g2), '(b)') 11 12 y = MT.iacwatershed(g1,g2) 13 adshow(MT.iapad(MT.ianeg(y)),'(c)')