Connected Component Labelling using Quadtrees - A Bottom-up Approach
A. Unnikrishnan · The Computer Journal · 1987
An algorithm to label the connected components of a binary picture is presented using a hierarchical version of the linear quadtree.2 This algorithm, which starts from the lowest level of the hierarchy, is shown to be computationally faster than the one using the topmost level as the starting point. The computational complexity of the algorithm appears comparable to that of existing methods due to Gargantini and Samet.4,5