
Figure 8.23d shows how area closing can be used to fill small aggregate holes
with area less than 200 pixels (c) that are specific to a texture, to form significant
clusters of interest. Similarly, small holes in Fig. 8.30g, having area less than 100
pixels, are closed and merged to recover the objects of interest (Fig. 8.30h).
In this section, we have introduced several component filters, their duals,
and their top-hat versions. That is, filters that do not introduce false edges
because they are able to select out (entirely) certain connected components of
the image, the selection being based on an area or shape fitting criterion.
8.2.6 Skeletonization