g2o usage

vertices and edges #

vertices indicates the state of the system, which is the variable to be optimized. edges indicates the measurement of the system, which is the constraint to the system.

pose estimation from 2d to 2d. #

all is done by openCV. the pipeline is as follows:

1. read image and extract features.
2. match features between two images.
3. use opencv to estimate the essential matrix.
4. use opencv to decompose the essential matrix to get the relative pose.