Continuous indoor visual localization using a perceptual Hash algorithm and spatial constraint
ZHANG Xing, LIN Jing, LI Qingquan, LIU Tao, FANG Zhixiang
Acta Geodaetica et Cartographica Sinica . 2021, (12): 1639 -1649 .  DOI: 10.11947/j.AGCS.2021.20200286