hide random home http://www.photosynthesis.com/vtvwebcam/howitworks.html (PC Press Internet CD, 03/1996)
VTV Webcam - How it Works

VTV Webcam - How it Works

Webcams are a dime a dozen on the Internet these days. In the quest for more telepresence, a number of sites have put their cameras on tilt/swivel mechanisms, to let visitors look around.

There are many limitations with this kind of mechanical solution:

  • Only one client can control the view at any time.
  • Mechanical bases are expensive, fragile, and require wiring to interface.
  • Mechanisms have physical limitations in how they move.
  • Having a camera wiggling around in our lab would annoy us.

    Using VTV to warp the signal from a very wide angle camera overcomes all these problems. When you request a view, a venerable IndigoVideo board grabs a wide angle image.

    This is what the raw video image looks like, a wide angle image close to 180 degrees.

    You are presented a dewarped view as a GIF. Clicking one of the surrounding buttons specifies a new yaw and pitch, and the view for that orientation is dewarped for you by VTV code running as a CGI program. State is saved in the html document generated by the CGI program, by a hack that uses the CGI parsing scheme for X,Y coordinates intended for image maps.

    Here's a picture of where you're looking from.

    Yes indeed, it's a small desktop teleconferencing camera, with a cheapo wide angle lens duck taped on. Nothing fancy, nothing mechanical.

    Click here to start VTV Webcam demo

    For faster dewarping, download our demos and get realtime video performance on a Pentium or SGI machine. Or better still, license our SDK and incorporate VTV into your applications.

    Return to Warp's Home Page