> I agree with you that what I want is a "smallest convex hull". 

Looking at the other answers I'm not sure anymore. A convex hull means a banana shape would be represented as a semicircle.

You seem to want a tight (not necessarily convex) vector graphic enclosing a sprite.

I think you could achieve this by improving the convex hull (by replacing long edges with concave triangles until all edges are sufficiently "short" or "tight")

Another problem I see are non-connected segments/territories . The shape of the USA would look very different if Alaska and Hawaii were included into just one hull ...

update

Found this http://stackoverflow.com/questions/7408470/given-a-vector-of-points-possibly-out-of-order-find-polygon-not-convex-hull

Pointing to the next problem There is no unique solution for a concave polygon

So starting from a convex hull and improving it till criteria are met is sensible.

Cheers Rolf
(addicted to the Perl Programming Language and ☆☆☆☆ :)
Wikisyntax for the Monastery

In reply to Re^3: Polygon Creation -- Request for Algorithm Suggestions (updated) by LanX
in thread Polygon Creation -- Request for Algorithm Suggestions by golux

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