1. A method for detecting a pedestrian exterior of a vehicle in an image-based monitoring system, the vehicle having an image capture device for capturing images exterior of the vehicle, the image-based monitoring system including a processor for processing image data received from the image capture device for detecting the pedestrian exterior of the vehicle, the method comprising the steps of: receiving input image data from the image capture device; applying a pedestrian edge-based detection analysis to the input image data for detecting a pedestrian candidate in the input image data, the edge-based detection analysis determining an edge-based confidence value for indicating a confidence level of the pedestrian candidate being a pedestrian; applying a pedestrian motion-based detection analysis to the input image data for detecting a pedestrian candidate in the input image data, the motion-based detection analysis determining a motion-based confidence value for indicating a confidence level of the pedestrian candidate being a pedestrian; determining a speed of the vehicle; applying a first weighting factor as a function of the vehicle speed to the edge-based confidence value and applying a second weighting factor as a function of the vehicle speed to the motion-based confidence value for determining a final confidence value; and comparing the final confidence value to a threshold value for determining whether to generate a warning that a pedestrian may be present in the input image data.