The analytics types: Objects counting in an area, Visitors counting, Line crossing detection. The camera placement requirements
To ensure proper execution of the Objects counting in an area, Visitors counting, Line crossing detection analytic types, an IP videocamera with relevant specifications should be properly placed and set up, taking into account the location and operating conditions in ways to capture images of the required quality.
In this guide, you will find the requirements for the main specifications of the IP videocamera, the camera placement, and the image requirements to ensure accurate performance of Objects counting in an area, Visitors counting, Line crossing detection.
The videocamera specifications
When selecting an IP videocamera, you should take into consideration the requirements for images to be received, the camera specifications, the installation requirements, the control zone peculiarities, and the location and operating conditions.
An IP videocamera should have the following specifications to ensure accurate performance of the Objects counting in an area, Visitors counting, Line crossing detection analytics types.
Specifications | Value |
---|---|
Matrix It is a key component of a camera that defines image quality. The value of this component reflects the size of the matrix diagonal in inches. | 1/3 inches and larger, with a high degree of sensitivity to light. |
Lens-aperture ratio (light sensitivity) Plays a crucial role in overall image quality. Lens aperture is the maximum light capacity of a lens, which determines how much light can pass through to the camera sensor. The F-number means the maximum size of the aperture. The smaller the F-number, the more light the lens can gather. | F1.4 and better |
Lens aperture With this camera component, you can set the amount of light that goes through the lens and control the focus depth. Located within the lens itself, the aperture regulates light intake by altering the size of the opening. | With adjustable settings (it’s important to be able to set the limits of the lens aperture opening and closing). |
The camera placement requirements
Below, you find the camera placement requirements to ensure proper execution of the Objects counting in an area, Visitors counting, Line crossing detection analytics types.
The distance and mounting height parameters
The video mounting height and distance to the objects of detection should be individually set for each camera. These parameters depend on the image quality captured within the recognition area and the required view angles for the relevant analytics type.
Angles and orientation
It is recommended to install the camera in a vertical position. Any other type of installation could negatively impact the proper execution of analytics.
The angle between the optical axis of the lens and the horizontal line should not exceed 45°.
For example, if a camera with a vision angle of 45° is mounted at a height of three meters, the blind zone will be equal to one meter from the camera projection onto the horizontal plane in the case of detecting a person who is 170 cm tall (see the image below).
The width of the area, before the blind zone, where a person is visible, is 2.5 meters. Only 2/3 of the person (the lower body part) will be visible at a distance of five meters. At this point, the camera’s field of view is about 13.5 meters.
![Group 11.png](../../../__attachments/5018059636/Group%2011.png?inst-v=5e52fa89-af48-462a-9bad-31c36e430795)
An example of the camera installation
Stable mounting
Ensure the camera is free from vibration.
Illumination
Illumination should be 150 lux or higher. The lighting conditions within the camera control area should be ample and uniform, excluding any side light sources. For example, to control the entrance group, prevent the camera from being illuminated by streetlights.
The depth of field
The camera depth of field should cover an entire control zone. The greater the depth of field, the larger part of the frame will be clear. The depth of field depends on the focal lens and the value of the lens aperture ratio. We recommend calculating the camera depth of field in advance (which is particularly relevant for long-focus lenses) and getting a camera with adjustable lens aperture settings (including the possibility to set the lens aperture opening and closing limits).
![глубина резкости.png](../../../__attachments/5018059636/%D0%B3%D0%BB%D1%83%D0%B1%D0%B8%D0%BD%D0%B0%20%D1%80%D0%B5%D0%B7%D0%BA%D0%BE%D1%81%D1%82%D0%B8.png?inst-v=5e52fa89-af48-462a-9bad-31c36e430795)
The depth of field
![image 14.png](../../../__attachments/5018059636/image%2014.png?inst-v=5e52fa89-af48-462a-9bad-31c36e430795)
Lenses with various camera aperture settings
The field of view and object counting
To ensure accurate analytics performance, a camera with relevant specifications should be placed according to the requirements. Additionally, the following requirements should be met:
Objects should be placed with the correct side up. If the captured image is upside down, it should be adjusted either horizontally or vertically via the camera menu settings.
![Group 12 (1).png](../../../__attachments/5018059636/Group%2012%20(1).png?inst-v=5e52fa89-af48-462a-9bad-31c36e430795)
An example of the correct image placement
The speed of objects shouldn’t be higher than 0.5–1.5 m/sec to avoid counting inefficiency
Objects should be visible at full height and shouldn’t overlap each other.
An image should be clear and sharp.
The illumination is uniform.
The background is neutral.
Avoid foreign moving objects in the detection area for the Objects counting in an area analytics type.
There is no limit to the number of objects simultaneously crossing the line (relevant for Visitors counting and Line crossing detection). However, missed detections are possible because of the high density of objects (see the image below).
![нежелательные условия для подсчета.png](../../../__attachments/5018059636/%D0%BD%D0%B5%D0%B6%D0%B5%D0%BB%D0%B0%D1%82%D0%B5%D0%BB%D1%8C%D0%BD%D1%8B%D0%B5%20%D1%83%D1%81%D0%BB%D0%BE%D0%B2%D0%B8%D1%8F%20%D0%B4%D0%BB%D1%8F%20%D0%BF%D0%BE%D0%B4%D1%81%D1%87%D0%B5%D1%82%D0%B0.png?inst-v=5e52fa89-af48-462a-9bad-31c36e430795)
An example of unfavorable conditions for object counting: the high density of objects