Documentation for C-Werk 2.0.

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Motion detection runs properly if video match the following requirements:

  1. Camera requirements:
    1. Camera shaking must not cause image shifting of more than 1% of the frame size.
  2. Lighting requirements:
    1. Moderate lighting. Lighting that is too little (night) or too much (bright sunlight) may impact the quality of video analytics.
    2. No major fluctuations in lighting levels.
  3. Scene and camera angle requirements:
    1. Moving objects must be visually separable from each other in the video.
    2. The background must be primarily static and not undergo sudden changes.
    3. Minimal obscuration of moving objects by static objects (columns, trees, etc.).
    4. Reflective surfaces and harsh shadows from moving objects can affect the quality of analytics.
    5. Long single-color objects may not be tracked properly.
  4. Object requirements:
    1. There is no noise on the video image and there are no artifacts caused by the compression algorithm.
    2. The speed of objects in the frame must be at least 1 pixel per second.

    3. In order to detect the object it is to be visible at not less than 8 frames.

    4. Within two adjacent frames the object cannot move in the movement direction for the distance that is longer than its size. This condition is essential for correct calculation of the object’s trajectory (track).

Some requirements depend on whether only a video motion detection will be used, or VMD-based scene analytics detection tools will be used as well. The difference in requirements is shown in the table:

RequirementsVMDVMD-based scene analytics detection tools

Resolution in pixels

Not less than 320х240Not less than 640х360
FPSNot less than 1Not less than 6

Image

Scene analytics only works with color imagesScene analytics works with both gray and color images

Size of objects in the image

The width and height of the objects in the image must be not less than 1% of the frame size (if resolution is over 704x576 pixels) or 15 pixels for lower resolution

The width or height of the objects in the image must be not less than 1% of the frame size (if resolution is over 1920x1080 pixels) or 15 pixels for lower resolution

Size of objects in the image relative to the frame size

The width and height of the objects in the image must not exceed 75% of the frame size

The width or height of the objects in the image must not exceed 75% of the frame size
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