网址：
1. https://blog.csdn.net/zijin0802034/article/details/77685438 (box regression 边框回归)
2. https://blog.csdn.net/shenxiaolu1984/article/details/51066975 (RCNN 算法)
3. https://blog.csdn.net/u014038273/article/details/78085932 （box regression PDF讲解）
4. 代码实现：https://github.com/Liu-Yicheng/R-CNN
5.https://blog.csdn.net/hjimce/article/details/50187029 (RCNN 算法讲解)
6.https://www.cnblogs.com/edwardbi/p/5647522.html （tflearn 代码实现）
7.https://blog.csdn.net/a8039974/article/details/83094671 (关于hard negative mining)