fangkd8

Results 2 issues of fangkd8

![sphere_g2o](https://user-images.githubusercontent.com/43018640/75841754-7fe1b080-5d9c-11ea-858e-71b4f0b25216.png) ![sphere_gtsam](https://user-images.githubusercontent.com/43018640/75841755-7fe1b080-5d9c-11ea-876b-d8dc28f82978.png) 使用的是同样的数据和代码,但结果差距非常大

In the projection part, your algorithm is to remove the points outside the camera frame by using distances and angles. But I cannot find the theory which support this way....