“…For an explicit description of the region-growing algorithm in the context of railways, the interested reader is referred to Cserép, Demján, Mayer, et al [37, Algorithm 1 and Algorithm 2]. Other examples of region-growing algorithms can be found in the work of Arastounia [23], Chbeir, Ponciano, Prudhomme, et al [32], Zhang, Wang, Yang, et al [22], Lu, Zhu, Bi, et al [80], and Zou, Fan, Qian, et al [70].…”