With the continuous development of technology, IP cameras have become a new type of monitoring system. IP cameras have significant advantages over analog cameras. We know that before video surveillance used a wide range of security applications, various types of CCD cameras were used. The so-called CCD camera, that is, the CCD as a sensor, the image signal acquisition and digital, after some image processing in a dedicated DSP chip, encoded into a CVBS analog signal transmission, CVBS is a composite video signal transmission through the coaxial cable The back-end DVR product performs analog-to-digital conversion, comb filtering (bright color separation) and other operations on the analog video through a video decoder, and encodes it into a digital signal for processing and output.
This kind of digital-to-analogue conversion from analog to digital has brought many problems. At present, some defects in security engineering come from this model. The main problems are: After the image is converted by analog to digital, the image is converted. Loss of quality; long-distance transmission of analog signals, severe signal attenuation, susceptibility to interference, poor image quality; image resolution fixed at PAL or NTSC, unable to meet higher definition, higher resolution monitoring requirements; video signal dynamics The scope is small, it is difficult to meet the needs of various specific applications, such as low noise, wide dynamic, high frame rate and other needs; unable to achieve distribution, long-distance transmission, sharing and other needs.
The IP camera adopts digital processing technology. After the video signal is collected and digitized from the CCD or CMOS sensor, all the subsequent processing uses digital signals and uses the network to transmit various specifications of the video signal. The adoption of the all-digital processing technology has the following advantages:
1. All-digital processing technology will not bring about loss of image quality due to back and forth conversion between analog and digital;
2. Digital video transmission using digital interface will not cause interference and attenuation, and it can always maintain stable image quality no matter how far away it is;
3. The scope of digital video is much larger than analog video, and it can achieve high-definition, high frame rate, wide dynamic video images;
4. Intelligent image processing and recognition technology can be extended to the front-end directly;
5. Wide dynamic video processing technology, can develop customized camera products for various occasions of video surveillance;
6. High-definition IP cameras can realize electronic PTZ functions and can meet a wide range of venue monitoring;
7. Can provide high-quality, high-bandwidth, low-latency preview video stream and video stream for recording, respectively, to ensure clarity and easy storage characteristics;
8. In the intelligent wiring system of the building, there is no need to carry out transformation and wiring. As long as there is an Ethernet network, a network monitoring system can be deployed at any time, and various wireless and wired networks can be used for video transmission and control.
9. Built-in storage devices, such as SD cards, small hard drives, can save critical video images to local storage in case of network failure.
As can be seen from the above, the emergence of IP cameras will make good use of various defects in analog cameras and improve them in all aspects. Compared with analog cameras, IP cameras integrate more information processing technologies and are closer to each other. User needs. In terms of cost, the IP camera chip can fully realize the functions of the original analog camera and provide the CCD's Bayer interface, which will not significantly increase the cost.