The following table contains the requirements for cameras to enable the effective operation of the visitor counter:
Camera | - Resolution: 720 х 576 (CIF4) or 360 х 288 (CIF1) pixel resolution. Using pixel resolutions higher than CIF4 do not lead to higher recognition accuracy.
- Frames per second: 25.
- Color: color camera is obligatory.
- No camera jitter is allowed.
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Illumination: | - Best recognition results are achieved under moderate illumination. If the scene is under- or over-illuminated, the recognition accuracy may drop down.
- Sharp changes in illumination may lead to improper operation of analytics.
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Scene and viewing angle: | - Vertically downward position is the best for the purpose. The closer to vertical, the more accurate counting.
- Camera FOV dimensions: min. 2 x 2m, optimal 4 x 4m.
- The background must be primarily static and not undergo sudden changes.
- The counting area must not contain any moving objects except for humans.
- Reflective surfaces and harsh shadows from moving objects can affect the quality of analytics.
- Leafage, TV screens or any periodic object movement in the background may cause analytics glitches.
- If possible, avoid obstruction of the humans by static objects such as pillars, trees, etc.
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Images of objects within the scene: | - Image quality: the image must be clear and sharp with no visible compression artifacts.
- Dimensions of a human in scene: the bounding rectangle must occupy 10–60 percent of the frame area.
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Other requirements: | - The visitors must not move in a continuous flow; smaller groups of humans are counted correctly.
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