Differential or intersection of islands of 2D polygons in different layers I have a 2D layer/section containing the 2D polygons colored in shades of green.
I have another layer containing the 2D polygons colored in shades of blue.

I intend to figure out how different are the two layers. Maybe extracting the layers differential. Can anybody provide an algorithm, library or a hint? I took a look at CGAL, but not quite sure which package to try out.
In CGAL, there is the Arrangement package that allows to build a topologically valid planar partition given a set of segments, and the Regularized Boolean Set-Operations that provides boolean operations between polygons.