There are four major points to pay attention to the development and production of HD network cameras.

From the testing of HD network cameras, it is found that the performance of HD cameras from various manufacturers is greatly improved and the design is more sophisticated. There are also 360° 4 million panoramic surveillance cameras specifically designed for indoor applications. Broad. Let us understand what to look for when developing and producing HD video cameras today.

Practical applications consider full-HD network cameras, many of which use structural designs that are more in line with engineering applications. The shell material selection, the use of good heat aluminum, aluminum alloy, steel, zinc and other metal shell, some products are also designed with ventilation holes. The functional interface is generally provided with a reset button for recovering the factory parameters of the camera, a BNC video output terminal for front-end debugging, a plurality of power supply modes, a front-end SD card storage slot under abnormal conditions, etc.; to facilitate the application of different transmission environments, Some manufacturers also choose a wireless transmission module for the camera. These designs allow the camera to be more in line with the installation requirements in actual engineering projects and are beneficial to maintenance in long-term applications. However, some manufacturers have highly integrated the interfaces for the convenience and stability of the installation of the cameras. They try to achieve the most functions with the least number of cables, such as parity and beauty.

High-definition image quality HD network cameras have adopted H. 264 compression algorithm, and usually have two or three codec formats at the same time, such as Axis uses H. 264 and M-JPEG, Li Ling is H. 264, MPEG4 and M-JPEG, Sony is H. 264, MPEG-4, JPEG. Under their respective compression algorithms, they all can display a clear picture quality of 800TVL or more. Among them, Huiyou's sharpness can reach 1100TVL, and U.S. praise can reach 1200TVL. Overall, it is greatly improved over the past; while in color reproduction performance testing In addition, except for very few products in a certain shade of light, the rest can be accurately restored.

In this test, in the 1080P resolution format, the bandwidth is limited to 4 mbps, and the bandwidth limit of the 720P resolution image output format is 2 mbps. Under different parameter restrictions, each product has a good code flow control performance, even if it is full. Frame transmission can also control the code rate within the limit. In terms of network delay, the network delays in the 720P resolution format are controlled at about 200ms, and the image network delays in the 1080P resolution format range from 290-400ms, most of which are controlled in more than 300 milliseconds. All the delays are Within 500ms, they are well-controlled. With good network control performance, all participating products can smoothly display moving images in a dynamic environment test.

The network control performance of a high-definition camera is greatly affected by the image processing performance of the camera. When maintaining high image quality, the camera's sharpness and color effect are good, but the network delay and code rate will be large; when it is to maintain transmission In real-time, when the chips and compression algorithms are not handled properly, the picture quality will be reduced. Therefore, manufacturers need to use high-performance processing chips and compression algorithms with good image processing performance in order to maintain the balance between image quality and network performance.

Strong environmental coping ability In the camera, almost all have a wide dynamic function, and have a very good performance in light suppression. In the low illumination test, the software design of each manufacturer is slightly different, and the day and night mode of some manufacturers' products is an adjustable automatic mode; the camera's sensor threshold can be set by the user and can be set to automatic or forced mode, and some But can not do automatic switching, can only select the night mode according to demand. However, their low illumination has a good performance, and they can still maintain a clean picture under extremely low illumination. In addition, Midea also uses infrared-assisted light sources to achieve low-light image rendering.

Lens Matching is Key Before the test, in order to check the impact of the lens on the camera imaging, we specially borrowed 8 different model lenses from lens manufacturers such as Tamron and Toray. When testing, we used the original lens test and replaced the borrowed lens with the camera. As a result, it was found that lenses with different focal lengths have different image quality effects. For example, telephoto lenses have good effects on long-distance vision, but close-range shots are blurred, which is not conducive to close-range presentation. Under normal circumstances, manufacturers have to match the camera with the best effect for the test product, so the effect of assisting the test lens is not all able to achieve the effect of the original lens; of course, there are some products because the lens is not matched, through the lens change After the test, it reached its proper definition. It can be seen that the lens is important for the camera imaging. When the manufacturers are researching and producing, it is necessary to choose a good lens so that the camera can achieve the best imaging results.