This patch demonstrates the video based long-term analysis of the displacement of a visitoractor in a scene. The right part of the video shows the blob tracking engine written in Java by François Zajéga, which segments and tracks the visitor from the incoming video stream and computes a series of basic features related to the 'blob' - i.e the entity corresponding to the extracted visitor. Position of the blob is then sent via OSC to a Max-MSP patch which computes the cumulated spatial occupation of the blob over a given time span (left part of the video).