Researchers from the Polytechnic University of Catalonia (UPC) and the University of Lovaina (UCL), in Belgium, have presented a technique that, using two video cameras to capture human movement, makes it possible to recognize body movements and display them in three dimension on a computer, according to the journal Multimedia Tools & Applications. The method can be applied to the development of interactive video games in which gestures are made with the hands and feet.
Engineer Pedro Correa, from the UCL Telecommunications and Teledetection Laboratory, told SINC that, together with professor Ferran Marqués's unit at the UPC, they have developed algorithms that tackle the problem of gesture recognition "in the least invasive way possible, since it does not require wearing any special suit or receivers, using a simple video camera to film the body's movement".
The images filmed identify the person's outline several dozens of times a second, and the data obtained are analyzed by the algorithm invented by the researchers to identify the "crucial points": head, hands and feet. The "crucial points extraction algorithm" uses the mathematical concept of geodesic distance to calculate the person's extremities, "in other words", clarifies Correa, "which points are furthest away from the center of gravity, following a path entirely within the outline".
Once the extremities have been obtained, the outline is analyzed once again to create "morphological skeletons" that help assign a label to each extremity. The five possible labels are head, left hand, right hand, left foot and right foot. Once identified, they are represented with colored dots for tracking in 2 dimensions. This enables the user to analyze the results visually.