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_cube 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.

Note

If a zivid or blaze camera is used instead of a stereo camera, only one camera image is provided. However, the image is rectified, i.e. lens distortion is removed and the principal point is in the image center.