Harbin Institute of Technology at Shenzhen Shenzhen 518000;
The University of British Columbia Vancouver BC Canada V6T 1Z4;
Harbin Institute of Technology at Shenzhen Shenzhen 518000;
Harbin Institute of Technology at Shenzhen Shenzhen 518000;
Harbin Institute of Technology at Shenzhen Shenzhen 518000;
Apple Grading; k-nearest Neighbour Method; Convolutional Neural Network; Support Vector Machine; Machine Learning;