11. The method of claim 10 , wherein the layout transition analyzing includes finding a pair of candidate block segments aligned in a vertical direction based on vertical layout transition features.
11. The method of claim 10 , wherein the layout transition analyzing includes finding a pair of candidate block segments aligned in a vertical direction based on vertical layout transition features. 12. The method of claim 11 , wherein the layout transition analyzing further includes finding another pair of candidate block segments aligned in a horizontal direction based on horizontal transition features in the layout.