Quality corresponds to some of the objectives of video surveillance, which are: to identify an unknown person, to recognize a known person, to observe a human action, to detect a human presence, etc. The usual criteria for identification, recognition, observation and detection are established according to the number of points (pixels) available to represent a human face. The usual criteria for identification, recognition, observation and detection are established according to the number of points (pixels) available to represent a human face, and there are also criteria for the legibility of a vehicle license plate.60 pixels are needed for identification to represent the width of a face that measures on average 15 cm (and 90 pixels for the height of the face, i.e. about 22.5 cm).

Horizontal resolution for the usual quality criteria:- Identification: 60 pixels for 15 cm or 400 pixels/m
– Recognition: 30 pixels for 15 cm or 200 pixels/m
– Observation: 9 pixels for 15 cm, i.e. 60 pixels/m
– Detection: 4.5 pixels per 15 cm or 30 pixels/m- Human eye plate reading: 60 pixels per 50 cm or 120 pixels/m- Human eye plate reading: 60 pixels per 50 cm or 120 pixels/m
– Automatic plate reading (ANPR): from 75 to 100 pixels for 50 cm, i.e. 150 to 200 pixels/m

● You now want to know how far you will be able to identify a person if you pass the 5 M pixel resolution. Simply replace the value 1920 by the new horizontal resolution, i.e. 2592 and you will get a distance of 2.14 m.
● You now want to know, with the same settings, how far you will be able to recognize a person. You then have to change the quality from 400 to 200 pixels/m. This will give a distance of 4.29 m.
● A 5 m wide gate is 50 m away from the point where you can attach a camera. To determine the corresponding angle, click on the angle pencil (which becomes a calculator) and enter the two values: « distance in m » 50 and « width in m » 5. The resulting angle is 5.7°.
Then determine the camera resolution you will need to identify a person.
Without changing the parameters, distance, width and angle, click on the pencil of the horizontal resolution of the camera (which becomes a calculator). Enter 400 for the quality in pixels/m. You get 2000 pixels of horizontal resolution.
● Up to what distance can you perform recognition with a 4k CCTN8EW01 camera?
Click on the « Distance in m » pencil (which becomes a calculator). Enter the known values, i.e. the horizontal resolution of the camera which is 3840, the quality in pixels 200 (note that this determines the « Width in m »), and the minimum horizontal angle of the camera: 46°. The resulting distance is 22.62 m and the width of the field you can monitor is 19.20 m.