1. In a computerized system including a camera mounted in a moving vehicle, wherein the camera acquires consecutively in real time a plurality of image frames including respectively a plurality of images of an object within a field of view of the camera, a method for determining a range of the object from the moving vehicle, the method comprising the steps of: (a) measuring in at least two of said image frames a dimension in the respective images of the object thereby producing at least two measurements of said dimension; (b) processing said at least two measurements thereby producing a smoothed measurement of said dimension; (c) measuring said dimension in at least one of said image frames subsequent to said at least two image frames, thereby producing at least one subsequent measurement of said dimension; and (d) calculating the range in real time based on said smoothed measurement and said at least one subsequent measurement.