I fixed the problems with holes in libdepixelize algorithm. Now the only blocker before work on B-Splines optimization is fix the position of T-junction nodes. I small video of the "polygon with holes": https://vimeo.com/72611259

And a small post describing the last algorithmic changes: http://vinipsmaker.wordpress.com/2013/08/13/splines-extraction-on-kopf-lisch...