“…Hence, a fast and intuitive lung segmentation and visualization method could have remarkable practical significance and clinical value for optimize screening efficiency. Thus far, many lung segmentation methods have been studied by researchers, see [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17] and references therein. Here, we classify them simply into two classes: the automatic segmentation methods and the interactive segmentation methods.…”