Table 2 Dimension of the parameter vector (COL vs. SRE)

Number of image frames

n _x

n _x

Number of observed landmarks

n _lm

n _lm

Focal length, principal point

2x3

2x3

Lens distortion (k ₁ , k ₂ , k ₃ )

2x3

2x3

Stereo baseline and relative orientation

2 + 3

2 + 3

Camera position and orientation

6 (n _x −1)

6 (n _x −1)

Landmark parameters

3n _lm

0

Total

11 + 6n _x  + 3n _lm

11 + 6n _x