visual odemetry
landmark in images
image features: harris, fast, ORB, surf, sift
discrbition: BRIEF
Attributions:
- locality
- reproduced repeatability
- distinctiveness
- efficiency
Fast feature
use the change of brightness in gray image
FAST-9/ Fast-12
Orentation: intensity centroid (brightness weighted center to position center)
guass-pyrimaid to solve scale. orentation to solve rotation
what is ‘steer BRIEF’
still hard to solve util now: feature matching (used for data association)
how to improve the matching: 快速近似最近邻 FLANN
esitmation movement of cameras:
if 2d information, use 对极几何
if 3d 2d, PNP
if 3d 3d, icp
optimization
guass-newton
ceres
g2o