“…However, in real cases, dark ship targets whose infrared radiation is lower than surroundings also exist in the backlighting infrared images. To detect dark infrared ship targets, Equations (4), (9), (8), and (10) in the Steps 1-5 of Algorithm 1 can be replaced by Equations (5), (12), (11), and (13), respectively, to compute normalized IFSM of dark ship image. Meanwhile, Equations (5), (12), (11), and (14) in the Steps 6-10 of Algorithm 1 can be replaced by Equations (4), (9), (8), and (15), respectively, to compute normalized BCSM of dark ship image.…”