Monitoring From Separate Video Input Sources on the Same Computer
A screen shot from a PowerMac 7100/80AV is shown below. It illustrates monitoring from two separate video input devices on the same computer, by running two copies of DeltaVideo. Macintosh cooperative multitasking permits multiple copies of DeltaVideo to share the same computer. The fields of view of the video cameras were deliberately overlapped for this example, so that common features could be observed. The resolution was 320 x 240 (half-size NTSC).
The upper portion of the screen shot shows the video recorded from Camera 1 (serial input); lower portion, Camera 2 (built-in video input).
The Volvo station wagon, moving from left to right (incidentally, on the legally incorrect side of the road), was first detected by the serial input camera (at 16h 44m 34.12s), before moving into the field of view of the other camera, which responded to motion more quickly. (The "dead time" of the serial input camera, under these conditions, was about 1 second.)
Exported versions (as PICT files, a two-click operation) of the frames from 16h 44m 34.12s and 16h 44m 36.45s are shown below. (Video was recorded at 16-bit depth; here, the 320 x 240 PICT files were converted to lower-resolution .GIF files for faster web download).
The monitoring "hot spots" were manually selected for both cameras, and are shown stamped on the frames as red rectangles, using the frame stamping options of DeltaVideo. The arrows indicate the most significant motion detected by DeltaVideo.