Unsatisfactory results of UAV images

[winmler]

Hi：
Thanks for your code. It is a really good work. But when I stitch UAV images using your code, I get a bad result. There are large distortions as follows. What's wrong with it?
3D result

2D result

My data：
link：https://pan.baidu.com/s/1uPS70rvgyj9Z1R_QoRKxrg
Extraction code：bs8j