Comprehensively solve the problem of camera backlighting
The Marshine line of Hydraulic Puller and Tensioners provides utilities and utility contractors the ability to improve productivity and efficiency while limiting downtime and improving job site safety. Hydraulic Puller and Tensioners from Marshine represent the next generation of stringing equipment. Features like negative self-acting hydraulic brakes, integrated hydraulic dynamometers, hydraulic cooling systems, advanced user controls and more make Marshine Hydraulic puller and tensioners the safest and most effective on the market today.
Hydraulic Wire Puller,Hydraulic Puller Set,Industrial Hydraulic Pullers,Hydraulic Hub Puller NINGBO MARSHINE POWER TECHNOLOGY CO., LTD. , https://www.marshine-power.com
Camera backlighting is a problem that is often encountered during the installation and debugging of monitoring projects. When the light is too strong at the door, it is easy to cause the screen to be black. At this time, we will find a way to adjust the position of the camera installation, but more often, the position of the camera is not casual. Can be adjusted, must be installed in the backlight environment, what should I do at this time?
Generally speaking, there are three main ways to solve the problem of backlighting the camera. One is to avoid direct sunlight when installing the camera; the other is to select a camera with corresponding improvement function, such as a wide dynamic camera or a backlight compensation camera; three can improve the illumination of the indoor light source. To reduce the contrast with outdoor light, let's analyze it one by one:
First, adjust the installation position of the entrance and exit camera, try to avoid direct sunlight from the outside, and can greatly improve the backlighting of the entrance and exit. For example, the bank door needs to be equipped with a camera to monitor the entry and exit personnel. If we install the camera facing the entrance and exit, we may encounter a more serious backlighting phenomenon, which will cause the captured monitoring screen to be black and the problem of shooting the real object. At this time, an experienced engineer will flip the camera that monitors the entrance and exit, so that the camera's lens is facing the person who walks out of the outlet. This is better than installing the camera against the entrance and exit, which can better solve the problem of backlighting.
That is to say, when installing the surveillance camera, we need to solve the problem of the installation location, and try to avoid installing the camera in the position of backlighting. The most important thing is to look at the effect and see the physical quality.
Second, the backlight is improved by selecting a camera with corresponding functions. There are two types of cameras in the security camera that can better solve the problem of backlighting of the camera. One is a camera with backlight compensation, and the other is a wide dynamic camera.
Backlight compensation, also known as backlight compensation, divides the picture into several different areas, each of which is exposed separately. In some applications, the field of view may contain a very bright area, while the contained subject is surrounded by a bright field, the picture is dim and layerless. At this time, since the signal level detected by the AGC is not low, the gain of the amplifier is very low, and the brightness of the main body of the picture cannot be improved. When the backlight compensation is introduced, the camera detects only one sub-area of ​​the entire field of view. The average signal level of this region determines the operating point of the AGC circuit. Since the average level of the sub-area is very low, the AGC amplifier has a higher gain, which increases the amplitude of the output signal, thereby making the subject on the monitor clear, greatly reducing the subjective brightness difference between the background picture and the subject picture. The visibility of the field of view is improved. Although the backlight compensation improves the brightness of the subject, the image quality is more or less degraded.
Wide dynamics are exposed twice at the same time, one fast, one slow, and then combined to make it possible to see both bright and dark objects on the screen at the same time. Both are designed to overcome the measures taken to see the target under strong backlight conditions, but the backlight compensation is at the expense of the contrast of the picture. In a sense, the wide dynamic technique is an upgrade of backlight compensation.
The backlighting phenomenon at the entrance and exit is often a very bright background and a very dark foreground target in the scene, and the position of the background and the target remains basically unchanged. The camera with BLC function (backlight compensation function) can be used only. An area is averaged to determine the AGC operating point. If the foreground target is located in the area, the clarity of the foreground target is expected to increase.
When we can't adjust the position of the camera, we can use a wide dynamic camera or a camera with backlight compensation to improve the entrance and exit backlight.
Third, improve the backlighting effect by increasing the illumination of the indoor light source. It can be imagined that the reason for the backlight phenomenon is that the contrast of the illuminance of the field of view is too large. The camera installed at the entrance and exit has strong outdoor light in the monitoring range, and the indoor light is weak, forming a black-and-white contrast of the image. Too strong. In this way, if the indoor light is enhanced by increasing the illumination of the indoor light source, and the contrast between the indoor and the outside is reduced, the backlighting phenomenon can be improved.
The backlighting phenomenon of the entrance and exit is a prominent problem in the process of video surveillance installation and use. For this problem, a completely effective method has not been found yet. The three methods described above have certain effects on improving the backlight phenomenon. We are using it. In the process, many conditions such as the integrated site environment are needed to consider and seek the best solution.
