1. A method for characterizing movement of an object having at least one feature, the method comprising: identifying data indicative of a plurality of pixels defining an apparent shape, apparent size and apparent position of the at least one feature from data indicative of a pixilated image of the object; classifying the at least one feature into one of a plurality of predetermined feature classes based on the apparent shape of the at least one feature; estimating an actual size of the at least one feature based on the classification; and determining a speed of the object based on the estimated actual size of the at least one feature, the apparent size of the at least one feature, a frame to frame change in the apparent size and the apparent position of the at least one feature, and a time between two frames.