7 cameras night vision ability misunderstanding

After years of accumulation and precipitation, the security intelligentization process has already blossomed in actual combat, with many opportunities. Among them, the demand for smart camera procurement has soared. In fact, compared with the daytime, the night is often a high-risk period of illegal behavior, and the surveillance camera nighttime imaging effect is not satisfactory, so the demand for night-time surveillance is actually priceless. AI ultra-light, black light, super star light... all kinds of concepts are endless, it is dizzying, don't make it clear, in case the customer is on the scene, accidentally lost a big order, big K intimately arranged 8 big cameras The night vision ability understands the misunderstanding and avoids stepping on the pit.

Misunderstanding 1: Nighttime imaging is for the eyes of the human eye

Understand one-sided.

The development of video surveillance has moved from analog video surveillance, network digital surveillance, high-definition digital surveillance to artificial intelligence monitoring. The camera already has the ability to recognize the content in the surveillance screen, and to think and judge, instead of the human eye to observe the world.

Nighttime imaging is not only for the human eye to see the target in the surveillance picture, but more importantly, to enable the monitoring device to automatically detect or identify the target and serve more advanced smart applications. We strive to give the camera a "night vision" capability through various technical means. It is not for the eyes of the human eye to watch the monitoring screen 24 hours a day, but to allow the machine to replace the person and complete the night monitoring task.

This misunderstanding led to a series of misunderstandings.

Myth 2: The human eye looks comfortable and the computer looks comfortable.

error.

People's perceptions are subjective and subjective. For the nighttime imaging effect of the camera, some people like to have less noise, some people like to be transparent, some people like sharp, some people like soft.

But what the human eye likes is not necessarily the "like" of the intelligent algorithm.

For the deep learning algorithm, it is hoped that the image data given by the camera is as much detail as possible, and does not require excessive noise reduction, smoothing, brightening, contrast enhancement, saturation enhancement, and the like.

Misunderstanding 3: Night imaging effect, think that the brighter the image, the better

Incorrect.

This misunderstanding is still derived from the monitoring screen for the sake of eye-catching. The above examples are not described here.

Misunderstanding 4: Seeing is equal to seeing clearly

Ignore the scene and understand one-sided.

Here is an example of a superstar camera.

The Super Starlight camera adopts a lens with a large aperture to enlarge the amount of light and enhance the brightness of the image. It usually works at night shutters at 1/25s, the image is very clear, very bright, and the night is as white.

However, it is necessary to capture the moving objects such as motor vehicles, non-motor vehicles and pedestrians at night, and it is necessary to raise the electronic shutter of the camera according to the traveling speed of the object, otherwise the pictures captured by the moving objects will have obvious tailing.

As the shutter speed is increased, the brightness increase caused by the large aperture lens is offset, resulting in loss of picture detail and increased picture noise.

Myth 5: Starlight cameras don't rely on light

error.

The clear, moonlit night has an illuminance of about 0.1 to 0.01 Lux, and the star-level camera maintains full color at an illumination of between 0.01 Lux and 0.001 Lux. The superstar camera can remain in low light conditions below 0.001 Lux. Full Color.

If the ambient lighting conditions are in lower illumination, the starlight camera needs to rely on the fill light, otherwise the sensor can still collect information, but in this case the noise information is also very large, let alone see the target, see the target will also compare difficult.

Myth 6: Black light does not need to fill light

error.

First introduce the technical principle of the black light camera. Black light: mainly uses two star-level image sensors, through special optical components, one of which collects image brightness information and object contours through infrared fill light, and another collects color information. Then, the image information is merged by the image fusion algorithm to output both bright and colorful images.

It can be seen from the technical principle that the sensor that first collects the brightness is realized by relying on the infrared fill light, and the other camera that collects the color needs the ambient light like the ordinary camera. In the dark and dark environment, the black light camera also has Rely on the fill light to fill the light.

In addition, when encountering some objects with infrared reflective materials, cameras using black light technology also have certain drawbacks in color reproduction.

As an example, because the clothes worn by the driver are black anti-infrared materials, the image restored by the black light technology restores the black clothes to white, which is bound to cause some troubles for subsequent illegal evidence collection.

Myth 7: The fill light is flooding, no need to pay attention

error.

In the early days, due to the limitations of imaging technology, the camera should look at the face and license plate information of the passengers in the dark under the condition of light. It is common to use high-intensity strobe lights to fill the light, so at some intersections in some cities. Rows of "sparrows" and dazzling "flash lights" are commonplace.

Walking on the city road at night, the cold will be "flashed." It is understood that the brightness of the "flashing lights" in the bayonet system is very strong, which can cause short-term "blind spots" on the human eye. Similar to ordinary glare and black under the lamp, it will be the underlying visual cells of the eye. And the visual nerve causes temporary damage. Especially in the road bayonet, the flash will cause a short-term blind spot for the driver while driving at night, laying a safety hazard for driving.

It is not a matter of course to be commonplace. At present, such defective systems are being phased out by the industry.