3) Polygon Approximation using Min. Perimeter Polygons:
A digital boundary can be approximated with arbitrary accuracy by a polygon.
For a closed boundary, approx becomes exact when no. of segments of polygon = no. of points in the boundary.
Goal of poly. Approx is to capture the essence of the shape in a given boundary using fewest no. of segments.
Min. Perimeter Polygon (MPP):
An approach for generating an algorithm to compute MPPs is to enclose a boundary by a set of concatenated cells.
Think boundary as a rubber band.
As allowed to shrink, it will be constrained by the inner & outer walls of the bounding regions.