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.

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.

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.

Images of objects within the scene:

• image quality: the image must be clear and sharp with no visible compression artifacts;
• the allowable size of a person is described in the Requirements for the person size in the frame.

Other requirements:

• the visitors must not move in a continuous flow; smaller groups of humans are counted correctly.