Since its birth, the network camera has been for 15 years. It is no longer a "baby" to start and it is no longer an "unsurprising successor of monitoring solutions." It has become a true choice for users. More and more network cameras have been deployed by users to their systems and applications.

This year, we truly felt that the popularity of network cameras has greatly increased. The advantages of the network camera have not changed in nature: providing more clear and high-quality images, and making the video surveillance more intelligent through close integration with the network. However, with the advancement of technology, these advantages and characteristics have been greatly strengthened, and are more prominent and significant.

Advantage 1: Bringing high image detail One of the advantages of the webcam is that it enables video surveillance to go beyond the traditional PAL/NTSC resolution and frame rate limits, resulting in high-definition video with extremely high image detail. Even a 1 million-pixel network camera provides nearly 3 times the resolution of analog CCTV cameras. High-end network cameras can provide up to 5 million pixels or even more resolution.

However, high resolution is not the only progress of network cameras in the field of clear images. The introduction of HDTV into the field of video surveillance has really promoted the application of HD in the field of video surveillance. With megapixel resolution, HDTV means high-definition image detail. In addition, an HDTV HD network camera that truly meets industry standards ensures excellent color reproduction, full frame rate and 16:9 aspect ratio format.

The introduction of the MPEG-1 compression standard laid the foundation for digital television and promoted the development of modern television standards throughout the world. The Motion Picture and Television Engineers-SMPTE is the HDTV standards development organization. As the authoritative global film, television, video and multimedia standard setter, the organization has identified the two most important standards: SMPTE 296M and SMPTE 274M. SMPTE 296M defines a progressive scan using a resolution of 1280×720 pixels, and SMPTE 274M defines a resolution of 1920×1080 pixels for interlaced or progressive scan.

The HDTV application webcam means the image is more comfortable for eye observation, 25/30 full frame rate video and excellent color reproduction. The widescreen 16×9 image provided by HDTV is the ultimate choice after many years of research. It contains more effective video information. In fact, HDTV standards that are truly fully compliant with the HDTV standard provide a higher level of picture quality than ordinary megapixel or HD cameras, providing better full-frame-rate video.

In the fields of airports, railways, casinos, city surveillance, passport control, and factory production control, HDTV HD network video can provide more perfect solutions.

The current HDTV has three display resolution formats: 720p (1280×720, progressive), 1080i (1920×1080, interlaced), and 1080p (1920×1080, progressive), where p stands for progressive. Line), and i is interlaced.

Compared to HDTV, a megapixel network camera generally does not comply with any of the video standards and is more similar to the number of pixels of a digital camera image sensor. For example, a multi-megapixel network camera usually offers a limited frame rate. Megapixel network cameras also have many good applications, such as in applications that require extremely detailed video images, such as bank surveillance, transportation hubs, and other venues.

In addition, more than 3 million high-pixel network cameras can support the "multi-view" technology, divide a plurality of sub-scenes in a monitoring scene, each sub-scene video output as an independent stream. This is not only the replacement of multiple Pulsing cameras by a high-pixel camera, but also the establishment of a connection between global and sub-views. Supporting digital PTZ (pan/tilt/zoom) is another advantage offered by megapixel cameras.

Megapixel and HDTV webcams have many advantages. There are still many applications, standard resolution network cameras can provide the best solution. Standard resolution usually means D1 (720 × 576 pixels) resolution, SVGA (800 × 600 pixels) resolution. In complex light scenes, standard resolution cameras can be used to the maximum advantage when extreme sensitivity and wide dynamic range are required. Some standard definition cameras offer a higher frame rate than the traditional 25/30 frames per second and are suitable for capturing fast-moving objects.

The key is what you need to see? Of course, the demand for video surveillance changes tremendously. The most fundamental problem is usually two different preferences:

Panorama overview: In this case, the goal is to get a panoramic overview of the scene. For example, in a shopping mall, the main purpose of installing a camera may be to monitor and view its actions in the flow of people rather than personal identification. Or check whether the parking lot is full or free, instead of identifying or reading license plates for individual vehicles. For the above applications, enough resolution is required to cover the scene.

High detail: If you need to be able to identify people or objects in the scene. This may be a point-based monitoring, to clearly see the customer purchase of each item, or in some cases, the need to be able to identify the face. High-detailed images can be monitored more closely with web cameras equipped with zoom capabilities. HDTV network cameras will provide more detailed, clear details and higher resolution images than standard definition network cameras.

Seriously analyze your video surveillance needs. In general, the answer lies in the combination of SD network cameras, HDTV network cameras and megapixel network cameras. By balancing requirements, an IP monitoring solution can have the best cost-effectiveness and meet the required image availability.

Advantage two: H. 264 Technology Increases Bandwidth and Transmission Capabilities With the extension of the network, network cameras can be deployed more quickly and easily. Video, audio, PTZ control and alarm information can be transmitted on the same network cable, greatly simplifying system cabling. At the same time, network cameras began to support QoS, IEEE802.1X and other network standards and protocols.

QoS (Quality of Service) is the quality of service. For network services, the quality of service includes the transmission bandwidth, transmission delay, data packet loss rate, and so on. In the network, the quality of service can be improved by ensuring the transmission bandwidth, reducing the transmission delay, reducing the data packet loss rate and delay jitter.

A new type of network camera can indicate the priority of IP data streams generated by its own video and alarms. In a network with a well-configured QoS, these monitored video streams can be used as services with higher priorities without being affected by lower-priority services. Down through the switch, reducing video delay.

The IEEE802.1x protocol is a client/server based access control and authentication protocol. It can restrict unauthorized network users/devices from accessing the LAN or wireless LAN through the access port. 802.1x authenticates the user/device connected to the switch port before getting the various services provided by the switch or LAN. Before authentication passes, 802.1x only allows EAPoL (Local Area Network Based Extended Authentication Protocol) data to pass through the switch port to which the device is connected; after the authentication passes, normal data can successfully pass through the Ethernet port. The network camera that supports IEEE802.1x can better guarantee the security and privacy of the network.

Network camera support for QoS, IEEE802.1x and other protocols is a continuous extension of network video surveillance solutions. The application of network cameras in a unified network (multiple applications running on the same network), wide area networks, and even the Internet provides more Good technical bedding and support.

For the most important bandwidth problem of network cameras, H. The advent of the 264 technical standard provides a new way to use bandwidth efficiently. A new generation of compression technology. 264 is mature and supports H. The 264 compression-encoded chip already supports 1080p full-frame-rate video output and has been fully implemented in network camera products. H. Both 264 and MPEG4 belong to the inter-frame coding algorithm, but they have been significantly improved and improved in compression coding efficiency. Compared to MPEG4, H. 264 On the premise of guaranteeing the same image quality, the average code stream dropped by nearly 50%, which greatly saved the network occupied bandwidth and video storage requirements. H. The bandwidth consumption of the 264 HDTV 720p video stream is already comparable to that of the MPEG-4 D1 video stream.

H. The 264 introduces an improved inter-frame prediction mechanism, improves error correction and network compatibility, and has been supported and widely used in many familiar video fields. Choose H. The 264 algorithm can benefit the user from many different perspectives: the user can choose to greatly reduce the investment in network and storage under the premise of guaranteeing the existing image quality; also can choose to retain the existing network and storage equipment investment conditions. Next, increase the resolution of the video image, get a clearer video or increase the video frame rate, and get a smoother video. Use H. The 264 algorithm greatly promotes the development of HDTV and megapixel technology in the field of video surveillance.

H. As a reliable international standard for video compression, 264 has begun to completely replace MPEG4, becoming the representative algorithm for inter-frame compression. Together with the intra-frame compression representative algorithm MJPEG, it has become the mainstream algorithm standard for international video compression.

Advantage 3: Closely linked with intelligent video analytics technology With the extension of the network, the scale of video surveillance is constantly expanding, making intelligent video a necessary choice for surveillance. According to research, before a 4-screen monitor, an operator can only observe at most 20 minutes, and begin to miss important events. Therefore, after the deployment of hundreds, thousands, and tens of thousands of videos, intelligence is the inevitable direction for the development of video surveillance. But what kind of intelligent network video surveillance system is the user needs? Intelligent network video must meet the needs of the user's personalization.

At present, the implementation of intelligent video functions based on network video surveillance systems mainly adopts a central analysis method. This implementation method refers to the intelligent video analysis of the video stream transmitted back from the front-end camera through the video management software running on the back-end server, so as to realize the intelligent processing of the front-end video information; back-end server or back-end management software It needs to be responsible for the daily browsing of real-time video, playback of video recordings, and management of log events. It also needs to be responsible for intelligent analysis of each video. As the scale of the system grows, this approach will put enormous pressure on the back-end management resources and transmission bandwidth. It needs to be alleviated by improving the performance of the back-end equipment, such as increasing the server configuration, increasing the number of servers, and the number of switches. The resulting cost pressures led to the analysis of only part of the video.

Therefore, comprehensive intelligent video analysis will inevitably be realized in the form of “edge intelligence”. This implementation method refers to intelligent analysis of video information through the front-end network video device to implement corresponding intelligent video functions. In this system, the front-end camera uses the embedded video analysis service to analyze the captured video, and the system pressure is distributed on each front-end video device. Complex intelligent analysis can be preprocessed at the front edge and then transmitted to the back end, further reducing the pressure on the transmission bandwidth and the central server. Then realize the comprehensive intelligence of the monitoring system "every video is intelligent."

The openness of “edge intelligence” is very important, and it must be kept open. More intelligent analysis applications can be developed and deployed to front-end network cameras to meet various personalized needs of users.

Conclusion Whether it is to achieve better video, image quality, or close integration with the network, to achieve a comprehensive network of intelligent video, openness is the biggest change brought by the network camera. Only with 100% standardization, an open network video surveillance system can better protect user investment, and can continue to follow the progress of technology and meet the growing needs of users. This is the fundamental difference between an IP video surveillance system and an analog system.