1. A method for training a vehicle detection system used in a street occupancy estimation of stationary vehicles, the method comprising: defining first and second areas on an image plane of an image capture device associated with monitoring for detection of vehicles; receiving video-data from a sequence of frames captured from the image capture device; determining candidate frames that include objects relevant to a classification task in the second area; extracting the objects from the candidate frames; extracting features of each extracted object; assigning labels to the each extracted object; training at least one classifier using the extracted features of the labeled objects; and, using the at least one trained classifier to classify a stationary vehicle detected in the first area.