Research Article An Image-Based Gradation Calculation Method considering Crushed Stone Morphology Cang,1,2 Xin Ding,1 Li Pang,1 Liang Deng,1 and Zexiong Shi1 1School of Resources and Safety Engineering, Central South University, Changsha, 410083 Hunan, China 2Hunan Key Laboratory of Key Technologies for Hydropower Resources …Web