VTP: Voronoi Tessalation and Percolation
A "friends-of-friends" source detection algorithm. VTP is well suited to finding low surface brightness, irregularly shaped sources. The CXC tool vtpdetect is an implementation of the VTP method described in Ebeling et al. 1996, MNRAS, 281, 799.
See also the Detecting Sources in Imaging Observations - Using vtpdetect thread.