Method and device for online calibration of vehicle cameras

摘要

A method for determining the orientation of a video camera attached to a vehicle relative to the vehicle coordinate system is disclosed. Using a video camera an incremental motion is measured based on the optical flow of the video stream. A linear motion component and a rotational motion component are determined. Based on a determined rotational angle the incremental motion is classified as linear or as rotational. The directional vector of the linear motion is used to estimate the longitudinal axis of the vehicle, and the rotational vector of the rotational motion is used for estimating the normal to the vehicle plane. Based thereon the orientation of the camera follows.

主权项

1. A method for determining the orientation of a video camera attached to a vehicle relative to the vehicle coordinate system, comprising:
measuring an incremental vehicle motion in the coordinate system of the video camera based on the optical flow of the video stream of the video camera; representing the incremental vehicle motion by a motion consisting of a linear motion component and a rotational motion, wherein the linear motion component is represented by a directional vector and the rotational motion is represented by a rotation axis and a rotational angle; classifying the measured incremental vehicle motion as a linear motion or as a rotational motion based on the determined rotational angle; measuring at least one incremental motion which has been classified as a linear motion; measuring at least one incremental motion which has been classified as a rotational motion; using the directional vector of the at least one measured linear motion for estimating the longitudinal axis of the vehicle; and using the rotational vector of the at least one measured rotational motion for estimating the normal to the vehicle plane so that the orientation of the camera relative to the vehicle coordinate system follows from the vehicle longitudinal axis and the normal to the vehicle plane, which have been determined in the coordinate system of the camera, respectively.