Network security is inevitable

After continuous innovation of technology and directed development of market demands, there are also market standards for high-definition network monitoring. Under the condition that the main direction is certain, manufacturers are creating differentiated and unique products, which will bring more users. A good user experience, in order to form a stronger market competitiveness. HD network cameras are network cameras that can capture more than 720P (1280*720) of video at a resolution greater than 12FPS, and even reach or exceed 1080P (1920x1080). Shenzhen Shiguo Technology Huanggong pointed out that as long as it meets the 720P standard in the HD definition, it can be understood as a million HD pixel level for the industry. Therefore, in the entire monitoring field, the explosion-proof HD network camera is also called a megapixel explosion-proof network. Cameras, megapixel explosion-proof network cameras have many differences from traditional analog explosion-proof cameras and ordinary explosion-proof network cameras. The development of social security monitoring will surely move in a clearer and more intelligent direction. This will be the end of monitoring. Here, the author will discuss with you the monitoring of those things.

The necessity of network monitoring

Here, we talk about the inevitability of network monitoring on the development of the network. Everyone knows email, it has changed thousands of years of human understanding. Compared with traditional letters, email is faster and more efficient. In the enterprise, e-mail has gradually become an official document. The management of corporate records is not limited to paper documents, but also includes various types of e-mails. In social interaction, it almost replaced the previous form of letters. If there are targeted e-mail management, backup, companies can more effectively manage internal and external files. At the same time, it may also become a hidden danger for the company and become a channel for employees to leak out. According to relevant department investigations, about three-quarters of large companies in the United States use special software to check employees' e-mails to prevent leakage of company secrets. This is only one aspect of development. For today's topic, the monitoring of the network is an inevitable requirement of the market and the development of the society. In contrast to the video surveillance industry, the most popular in the past two years, in addition to the Another aspect of the NVR represented by the network should be high definition. In fact, for video surveillance, image clarity is indeed the most critical feature. Shiguo Zhuangxin said: Because the clearer the image, the more obvious the details, the better the user's viewing experience, and the higher the accuracy of smart and other application services. It can be seen that the introduction of high-definition performance will bring practical applications for video surveillance services. A series of all-round, dramatic improvements, and the importance of HD to video surveillance is self-evident.

HD monitoring concepts and technologies

Because high-definition surveillance has not yet been completely popularized and the technology is constantly developing, the concept of high-definition in the market is not yet clear. Therefore, before elaborating on the relationship between high-definition and NVR, we need to first understand the core concepts of high-definition surveillance:

First, HDTV HD standard system is the mainstream

After the video resolution of the monitoring device reaches megapixels or 720p, it can be called HD, and in fact, there is still a big difference between megapixel and 720p.

720p is derived from the HDTV standard developed by the Society of Motion Picture and Television Engineers (SMPTE). According to the standard, there are three main formats that truly meet HD video: 720p (1280*720) resolution, 1080i (1920*1080) resolution, and 1080p (1920*1080) resolution. This high-definition video standard originally used in the broadcasting and TV industry has also been commonly adopted by the video surveillance industry as a recognized technical standard.

The megapixel is not a recognized standard, but it actually refers to the number of image sensor elements of the network camera. When a high-definition IP camera has more than megapixel performance, it is still not known what the frame rate of this camera is, how the video aspect ratio is, whether it is interlaced or progressive, how the color fidelity is, and so on. It is also the main indicator of the performance of a high-definition IP camera. Therefore, as an industry standard, it is clear that the HDTV standard is more practical.

Second, H.264 will become the dominant video coding technology

HD video camera video coding standards are mainly MJPEG and H. 264 two kinds. MJPEG (MotionJPEG) is a dynamic image compression technology developed on the basis of JPEG. Although it has certain advantages, its defects are also very obvious, including serious drop frame phenomenon, poor real-time performance, low compression efficiency, large transmission bandwidth and storage space, etc. .

H.264 is a new-generation video coding standard developed by the joint video work group JVT jointly established by ITU-T and ISO. It not only saves more than 80% of the code rate of MJPEG, but also has better support for network transmission. As a result, broadcast-quality HD video resolutions of 720p and 1080i/p can be achieved at lower bandwidths.

Third, the front end of high-definition monitoring must be a high-definition IP camera

Traditional SD monitoring can be divided into analog, digital and network types. The front end of these monitoring systems can use analog cameras, network cameras, video encoder analog cameras and other types, but in high-definition monitoring, the front end must be high-definition IP camera.

First, the uncompressed high-definition video signal after the acquisition has both analog and digital transmission methods. No matter whether it is analog or digital transmission, the transmission cost of uncompressed high-definition video signals will be much higher than the previous analog SD video. The signal, therefore, can see that the transmission of high-definition video signals cannot continue to use the transmission methods of SDTV systems in the past, but can only compress and encode the video and transmit it through the IP network, and adopt this transmission method and the transmission of the SD system. The difference in cost is minimal.

Second, due to the high cost performance of CMOS high-definition video sensors, the efficiency and cost of directly using high-definition network cameras for front-end processing are more advantageous than those of high-definition video encoders.

Through a brief introduction to the core concepts of high-definition monitoring, next, we introduce the network of the monitoring back-end, and now the network monitoring back-end uses NVR, the explosion-proof high-definition network monitoring of the World Technology, and the use of high-quality monitoring back-end NVR. Although monitoring NVRs have many innovative advantages, the true popularity still needs a core competitive feature to drive, and the high resolution, high fluency, and large-screen and wide-screen displays that can be brought about based on the above HD technologies can be significantly improved. Improving the ease of use of the monitoring system and the performance of the user's image browsing experience coincided with the requirements of the NVR's core competitiveness. At the same time, since the basic premise of high-definition monitoring must be networked, the combination of high-definition and NVR is a matter of course.

Finally, coupled with the excellent quality of NVR itself, including the integrated functions we already know and recognize, including access management, video storage, and decoding, we believe that in the era of high-definition surveillance, NVR will be able to face unprecedented development.

Using megapixel sensor, can get more video information, generally up to 1280×1024, 1392×1024, 1628×1236 or even 2048×1536 resolution; using megapixel lens, test ordinary lens in the same environment With a megapixel lens, a megapixel lens can better fit a megapixel sensor for a sharper image. Higher image quality, better capture of details, progressive scan CCD/COMS dynamic picture performance, support for HDTV widescreen output mode (16:9), wider coverage, same surveillance area can replace the original Multiple fixed-point cameras and one omnidirectional camera.

The sharpness of the explosion-proof camera depends on the performance of the sensor. Compared with the CMOS sensor, the CCD sensor is superior to COMS in terms of sensitivity, resolution, noise control, high-quality image output, and dynamic image performance, so the analog camera SD network cameras mostly choose CCD as the photosensitive element. However, the CCD has a low response speed and is not suitable for the high resolution progressive scan method adopted by high-definition surveillance cameras. Therefore, explosion-proof HD network cameras generally use CMOS photosensitive elements.

The image compression format directly determines the requirements for the transmission network, video storage, and back-end processing, and also greatly affects the image quality. Currently widely used image compression technology in explosion-proof HD network cameras is JPEG/MPEG-4/H. 264 Three ways, each with different characteristics. For example, JPEG can obtain the highest single-picture quality, and the processing platform requirements for the camera itself are also lower, but it takes up the largest bandwidth for continuous image compression; 264 can get the highest compression ratio, but the camera itself has the highest processing platform requirements. In order to adapt to different application requirements and network environment, the relatively high-end explosion-proof high-definition network cameras all have these three encoding capabilities and dual-stream and multi-stream capabilities.

Problems with HD surveillance

Explosion-proof HD network cameras have made a qualitative leap in image clarity, but they have also brought a series of real problems to the high-definition monitoring system:

1, the network bandwidth is tense: The greater the resolution, the clarity is ultra high, mean the code stream will be increased while carrying on the data transmission, increase the network bandwidth pressure;

2. The storage space is huge: the data traffic doubles, increasing the video recording capacity and putting pressure on the network storage.

3. The demand for central control, management software, and hardware performance has increased exponentially;

4. The workload for the management and post-mortem analysis of recorded video images will also exponentially increase;

5, high investment costs.

Therefore, while pursuing high image quality, businesses must also consider solving the above problems for customers.

HD monitoring on demand application

The technical challenges faced by the high-definition surveillance mentioned above can be solved by applications. According to the current situation, users should not blindly pursue high definition. If all front-end monitoring points use explosion-proof high-definition network cameras, and all use real-time high-definition transmission, the back-end storage and transmission will cause great pressure and cause cost and efficiency waste. Therefore, suitable solutions should be designed according to the needs of users. For example, high-definition megapixel network cameras are designed and installed in high-risk areas. Under normal circumstances, only ordinary resolutions (CIF, D1) are used to transmit real-time video images, and alarm conditions occur. High-resolution images are transmitted in high-resolution JPEG format for later viewing and control of details. This can greatly ease network pressure, storage pressure, and reduce investment costs.

Three-stream high-definition network cameras are currently available in the market, which support JPEG/MPEG-4/H respectively. 264 these three different video compression formats, according to different actual needs to match different programs, but also according to the actual situation of the customer to set these three kinds of code streams. For example: H will be lower stream. The D1 image in 264 video compression format is sent to the remote end for real-time monitoring of the client while megapixels of H. 264 Video Compression Format Real-time images are sent to the storage server for recording. In addition, megapixel JPEG images can be transmitted at the time of the alarm, making it easier to confirm afterwards and find suspicious objects.

In short, high-definition network monitoring will be the inevitable road of monitoring and development, it will also be the end of the point. Manufacturers in the design of these high-definition network monitoring products, as far as possible diversification, differentiation, making the choice of customers diversified, can also constitute their own product market competitiveness; users through different choices, to achieve a more reasonable match, resulting in higher Cost-effective, for businesses and customers to achieve better service and achieve a win-win situation.