Portable Structure Surface Crack Detection System Based on Android Platform Huifeng WANG, Haonan PENG, Yu TANG, Yueyuan GUAN, Yaru LIANG, Lisha WANG, Yu ZHAO, Xiaoyan WANG, Rong GAO and He HUANG Wuhan Univ. J. Nat. Sci., 29 2 (2024) 154-164 Published online: 14 May 2024 DOI: 10.1051/wujns/2024292154