The Perceptual Browser Movie (Power Macintosh)

To view the movie in this page, your browser must be able to display an mpeg movie using one of its plug-ins. On Macintosh or Windows, the QuickTime plugin displays any kind of movies.

At the beginning of the movie, a target to track is manually choosen (yellow square). The speed and robustness of the tracking is shown. Then, the control of the window scrolling is demonstrated, once with the tracking window displayed, once hidden. The user has to scroll the browser window (at the top-right) to find all the grey blocks and to click on them.
In the tracking window, the red square represents the current location of the target, the green one represents the area that was searched to find the target.
The system runs on a Power Macintosh (processor PPC604 at 350 Mhz with 1 Mb of backside cache at half the processor frequency). The tracking running frequency is more than 60 Hz with a 32x32 target and a 60x60 search size. Using such a big target allows a good tolerance of the tracking to head rotation and scaling.
Scrolling the window content consumes a lot of processing, so the overall running frequency (when the browser window is scrolling) typically drops down to 12 Hz.
A shorter movie shows the tracking behavior with smaller target and search sizes, and a smaller running frequency due to its execution on a less powerfull architecture.

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PBrowser François IIHM CLIPS IMAG

created on July 10, 1998 by François Bérard.