Rectification

To simplify image processing, the camera module rectifies all camera images based on the camera calibration. This means that lens distortion is removed and the principal point is located exactly in the middle of the image.

The model of a rectified camera is described with just one value, which is the focal length. The rc_visard NG reports a focal length factor via its various interfaces. It relates to the image width for supporting different image resolutions. The focal length \(f\) in pixels can be easily obtained by multiplying the focal length factor by the image width in pixels.

In case of a stereo camera, rectification also aligns images such that an object point is always projected onto the same image row in both images. The cameras’ optical axes become exactly parallel.