Teach you to debug the installed high definition camera

Since the development of China's monitoring industry, the picture quality requirements for surveillance camera monitoring are getting higher and higher. In view of the market demand, high-definition cameras have entered the field of vision and started to occupy a certain share position in the market. Everyone is buying, installing and debugging. In the process, how can we produce the highest clear monitoring picture? The following small series is simple to introduce you.

HD surveillance camera installation and commissioning

In the general security monitoring system installation, the installation and debugging methods of the HD camera and the ordinary camera are basically the same, but it is necessary to pay attention to the lens matching, because the quality of the lens is not good, or the matching is not good, which will greatly affect To the clarity of the picture, for example, the infrared night vision system camera is best to use the infrared lens, while the 1/3 inch CCD is usually equipped with a 1/3 inch lens, and the 1/2 inch CCD is generally equipped with a 1/2 inch lens. The focus adjustment of the lens must be adjusted during debugging, especially the back focal plane of the camera should be adjusted. In many cases, the unfocused focus of the lens will cause the image to be blurred, which will not meet the high definition requirements. In addition, the protective cover of the camera can not be ignored. The front glass of the gun-type protective cover cannot use ordinary flat glass, but must use better optical glass. The general flat glass has a very powerful weakening effect on the resolution of the image. The spherical cover should pay more attention to the fact that the curvature of the spherical surface must be smooth. It is best not to align the lens with the upper edge of the spherical shell. Here, the refractive power of the light is large, which may seriously affect the sharpness of the image. It is very important that no matter which kind of cover, it is better that the light in the cover is as low as possible, and the distance from the lens to the cover is as short as possible, so that the light pollution in front of the lens can be minimized, which is beneficial to improve the image. The clarity.

HD surveillance camera system must be HD

In addition to the front-end installation and material selection, high-definition cameras must also have a transmission system, and the intermediate system and the terminal display system can be used together to achieve high-definition effects.

For the HD surveillance camera system, the transmission of video images generally selects coaxial cable, twisted pair cable, UTP cable (ie network transmission), wireless transmission, optical cable transmission, etc., regardless of the transmission method, the image must be The bandwidth of each ring in the entire system transmitted to the back end is >6M, so as to ensure the high definition of the image and meet the requirements of engineering and technical detection. Under normal circumstances, the image quality will be significantly reduced when the coaxial cable exceeds 150 meters or 200 meters. This is due to the characteristics of the coaxial cable itself. Therefore, various measures must be taken to ensure that the terminal bandwidth is not less than 6M. The video compensation amplifier is used to solve the problem, and the general video amplifier does not have much effect. The compensation index should ensure that the high-frequency compensation amount, the amplitude-frequency characteristic, the signal-to-noise ratio, the common-mode rejection ratio, the differential phase distortion, the chrominance luminance delay, and the chrominance width gain are all caused by the loss or attenuation of the relevant cable. Defects are compensated to ensure high definition of images entering the system.

At present, due to the rising price of copper cables, the cost of transmitting video images using optical cables is declining. In the transmission of longer distances or multiple images, the use of optical cable transmission is a widely used solution. Due to the large bandwidth, low attenuation, high anti-interference, small size and strong confidentiality of the optical cable, the indicators of image transmission can be well guaranteed. When transmitting images in other ways, the bandwidth of the channel must also be guaranteed.

High-definition images must also be represented by a good terminal display device in front of human vision, so it is best to choose a progressive scan monitor. Because the image of the interlaced scan monitor flickers seriously in actual use, it is easy to cause visual fatigue. If the clarity of the monitor is low, the overall resolution is not met. Because the resolution of the monitor is determined by the monitor, the bandwidth of the video channel, and the pitch and distance of the picture tube. According to the data, the theoretical upper limit of the conversion between channel bandwidth and resolution is about 1M/80 lines. If the video signal amplitude drop factor in high definition is considered, to display the 400 line video image, the monitor is clear. The degree index should be more than 600 lines of machine by experience. In order to make the HD surveillance camera system work properly, intermediate processing equipment, including matrix, DVR, video server, various video encoders, etc., must meet the bandwidth and image compression requirements, so that high-definition cameras can fully utilize their internals. The role. The use of high-definition cameras and the neglect of other ancillary equipment are not for the real purpose.

Summary: Through the above debugging, it is not a problem to get the highest picture quality.