A method for tracking objects entering and exiting an environment comprises providing stereo vision cameras positioned proximate to the paths to enter the environment, such that the stereo vision fields associated with the cameras substantially cover the paths. Using image data obtained by the stereo vision cameras, entry signatures are determined for objects entering the environment and exit signatures are obtained for objects exiting the environment. At any time after the determination of at least one exit signature, exit signatures are matched with the set of available entry signatures. Matching may be performed according to a variety of techniques.