Improve irregular boundaries

[balazsdukai]

Goals:

• Reduce irregular boundaries in final roof partition
• Reduce complexity of initial roof partition

Todo:

• Line regularisation: cluster on distance in general between line segments, not just perpendicular distance

• Line regularisation: cluster with moving average for each cluster/implement proper hierarchical clustering

• compute more accurate extend for intersection lines

• In initial line roof partition (the arrangement prior to graph cut optimisation): insert only the line segments, not full lines

• do not merge clusters if both contain an intersection line (or split again after clustering?)

• test on large area

• remove complexity limit in graph cut optimisation node. Maybe put it in the regularisation node...

• Make new clustering algorithm faster. 1) Use a binary min heap for the distance table/finding minimum distances, 2) keep for each cluster a std::list with heap handles to the distances involving the cluster (for faster distance update after a merge).