Segmentation of Pipe Images for Crack Detection in Buried Sewers. Comput. Aided Civ. Infrastuct. Eng. 2006, 21, 395–410. [CrossRef] 15. Castleman, K.R. Digital Image Processing; Prentice Hall, Inc.: Englewood Cliffs, NJ, USA, 1996. 16. Nishikawa, T.; Yoshida, J.; Sugiyama, T.;...