A method for detecting contour points of an object in an image obtained by a video camera comprising the steps of: (i) selecting a scan line of the image; (ii) identifying minimum intensity differences called transitions between pixels of the selected scan line; (iii) identifying plateaus at both ends of the identified transitions; (iv) determining contour points of the object between the identified plateaus; (v) generating a descriptor of the contour in one dimension; and (vi) beginning again with step (i) by selecting another scan line of the image according to a predefined order.