8Curto J J, Blanca M, Martine E. Automatic sunspots detection on full-disk solar images using mathemati- cal morphologys[J]. Solar Phys, 2008, 250:411- 429.
9Yoshioka M, Omatu S. Filter defect detection meth- od using rotational morphology[J]. Artif Life Robot- ics, 2009, 14: 20-23.
10Li Lili, Ma Guoqing, Du Xiaojuan. Edge detection in potential-field data by enhanced mathematical mor- phology [J]. Pure Appl Geophys, 2013,170.. 645- 653.