Method for determining a current distance and/or a current speed of a target object based on a reference point in a camera image, camera system and motor vehicle

A method for determining a distance and/or a speed of a target object relative to a motor vehicle based on at least one image of the target object, the method comprising:

• extracting characteristic features of the target object from the at least one image, the at least one image being provided by a single camera of a plurality of cameras of the motor vehicle;
• determining a reference point associated with the target object based on the characteristic features;
• determining the distance and/or the speed of the target object based on the reference point;
• and
• determining a baseline in the at least one image based on the characteristic features, the baseline being in a transition area where the target object intersects a ground surface in the at least one image,
• wherein a point located on the baseline is determined as the reference point,
• wherein the baseline is a straight line in the at least one image and delimits a bottom edge of the target object, and
• wherein determining the baseline comprises:
• determining an orientation of the baseline in the at least one image,
• determining an auxiliary line along the orientation and disposed above the target object in the at least one image,
• measuring a distance in the at least one image between each of the characteristic features and the auxiliary line, and
• selecting, among the characteristic features, a ground feature that has a greatest distance to the auxiliary line,
• wherein the baseline is parallel to the auxiliary line and extends through the ground feature, and
• wherein the characteristic features of the target object are tracked over a sequence of images,
• wherein optical flow vectors are determined as being the characteristic features, directional values of the optical flow vectors characterizing a direction of movement for each of the characteristic features over the sequence, and
• wherein an orientation of the baseline is determined based on the directional values of the optical flow vectors.