We want to run the fit on the non-centered points to yield the center
of the ellipse in the returned array.

This class mainly manages a collection of epicells, has
static methods for its creation from images, and has some
methods for plotting things.

The transform back is not correct yet.
See how to make the fit and rotation with respect to point centers,
then translate ellipse back at the right coordinates.

Subfunction that does only fit on 2d points (no matrix rotation).
Fixed the quadratic to cartesian conversion.

and back.

Like S. Herbert did.

Now we work more like a class with methods.

Small enough to be committed.
Images by Leo Valon, Institut Pasteur, Levayer lab.

- We smooth the height-map by a scale automatically determined by
object scales -> avoid jagged edges.
- We prune effectively regions where Z = 0.
- Compute and display de-project area.

- Directly permute X & Y to have boundary coordinates in the proper
referential, like junctions.
- Reduce the number of vertices in the polygon, using reducepoly.
With this setting (0.005) reducepoly is very conservative, but
effectively decimate useless vertices. This has a positive impact
on the area calculation (fewer, larger triangles), and on all
performance.