(meteorobs) ELP Bolide 05/04/06

[Jim Gamble]

Jan,
    In an attempt to conserve enough memory to produce 6 seconds of video, "Sentinel" buffers 12 frames prior to an event and grabs the first frame as a full picture base upon which to track an object. Then Sentinel centers the object in a 168 x 168 pixel box and tracks the event as a much smaller overlay across the base image thus eliminating the need to record the full 640 x 480 pixel image in every frame. This produces the "box" effect you describe.
    Hope this helps.
  Jim Gamble