1. A method for determining a risk of collision between a host motor vehicle and a pedestrian using a camera and a processor mountable in the host motor vehicle, wherein the processor is operably connectible to the camera and the processor is configured to capture a plurality of image frames from the camera of the environment of the motor vehicle in the field of view of the camera, the method comprising: detecting an image patch in at least one of the image frames, wherein the image patch includes a candidate image of a pedestrian in the field of view of the camera; providing a collision warning or a collision prevention control signal if the pedestrian is on the far side of the curb or lane mark and is crossing the curb or the lane mark; or inhibiting a collision warning or a collision prevention control signal if the pedestrian is on the far side of the curb or lane mark and the pedestrian is not crossing the curb or the lane mark.