1. A system for processing a digital spatio-temporal input signal containing zero or more foreground objects of interest superimposed on a background, the system comprising: a camera producing data representing images from which the spatio-temporal input signal is derived; a foreground/background separation module operating according to one or more adaptable parameters, the foreground/background separation module receiving the spatio-temporal input signal as an input and producing as outputs foreground/background labels designating elements of the spatio-temporal input signal as either foreground or background; a foreground object grouping module connected to the foreground/background separation module, the foreground object grouping module identifying a group of selected foreground-labeled elements as a foreground object; an object classification module connected to the foreground object grouping module, the object classification module generating object-level information related to the foreground object; and a feedback connection between the object classification module and the foreground/background separation module, by which the object-level information adapts the one or more adaptable parameters of the foreground/background separation module.