“…[175] is the first survey paper for BUS image segmentation published recently; however, this paper is much more comprehensive in terms of major issue discussions, future direction prediction, theory fundamentals, application theme and the number of references. In this paper, we classify breast cancer segmentation approaches into six main categories: (1) graph-based approaches [7, 9-13, 22-25, 27, 28, 32-34], (2) deformable models [42, 50, 52, 54-59, 61-65, 67, 69, 71, 73, 75, 76, 78-82, 85, 124, 139, 148, 166], (3) learning-based approaches [7,9,10,87,89,91,94,95,98,100,[103][104][105][106][107]120], (4) thresholding [22,[109][110][111][112][113][114][115], (5) region growing [54,55,113,117,118], and (6) watershed [109,122,123,[126][127][128]. As shown in Fig.…”