Module city2ba::noise

Functions for adding noise to bundle adjustment problems.

[../BAProblem]s generated from the [../generate] or [../synthetic] modules do not contain any noise. To test software against bundle adjustment problems, error needs to be added in. Many different kinds of error exist, but usual sources of error in bundle adjustment problems include:

• Error from incorrect camera intrinsics.
• Error from initialization drift (add_drift, add_drift_normalized).
• Error incorrect correspondences (add_incorrect_correspondences, drop_features, split_landmarks, join_landmarks).

In addition, this module provides functions to add less realistic noise:

• Local error for every camera/point (add_noise).
• Long range error (add_sin_noise).

Functions

add_drift	Add drift-like noise to the problem. Each camera is transformed like so:
add_drift_normalized	Add drift noise to the problem in the direction of standard deviation of the problem. See add_drift.
add_incorrect_correspondences	Add incorrect correspondences by swapping two nearby observations.
add_noise	Add Gaussian noise to a problem.
add_sin_noise	Add noise to the BAProblem in the form of a sin wave. Noise is sin(dot(x,dir) * frequency * pi) * strength * noise_dir where x is the normalized distance of the camera/point from the origin (in the range 0-1).
drop_features	Drop camera-point observations.
join_landmarks	Randomly join two landmarks into a single one for some camera observations.
split_landmarks	Split landmarks into two different landmarks at the same location. Observations as split randomly between the new landmarks.