Novel and powerful 3D adaptive crisp active contour method applied in the segmentation of CT lung images.

•The 3D Adaptive Crisp Active Contour Method (3D ACACM) is proposed for the segmentation of CT lung images.•A new 3D adaptive internal energy is defined to optimize the segmentation.•The automatic initialization of the 3D ACACM is described.•The 3D ACACM is compared against three methods commonly used in this domain.•The results confirm the superior effectiveness of the 3D ACACM.