Over time, HD surveillance is increasingly participating in the construction of a safe campus. Most new projects, or expansion projects, will deploy several high-definition cameras at key monitoring points. Even in some universities in economically developed regions, some new projects have already appeared in full HD systems. There are a variety of video systems on campus: Ping An Campus, Examination Room Monitoring, Recording and Broadcasting System, etc. Among them, Ping An Campus is closely related to campus security. The image requirements are relatively high. With the high-definition monitoring, it is more and more recognized by users. The Ping An campus is basically a full HD system, and most of the original SD systems have also been switched to HD in general. It can be said that HD surveillance has spread to every corner of the campus. There is also a typical characteristic of the campus. The campus network is a LAN/campus network with relatively sufficient bandwidth and relatively convenient expansion. This is in stark contrast to the tight bandwidth metropolitan area network and wide area network. Therefore, campus monitoring is more suitable for consumption. High-definition (720P, 1080P) monitoring system with a large amount of bandwidth. With the increasingly mature and widely used applications of high-definition campus monitoring systems, high-definition surveillance has brought more and more changes to the campus monitoring, which has produced more and more profound impacts. Fewer camera deployment, fewer dead zones Seamless monitoring, or no blind zone monitoring, means that the moving object enters the arming area. Once it is out of the monitoring field of a monitoring point, it will immediately enter the monitoring field of another monitoring point, which is the ideal state of video monitoring. The campus coverage area is relatively fixed, the perimeter is clear, and the cost of seamless monitoring of campus monitoring is lower and the possibility is higher. With the development of the economy, the students' thinking is increasingly active, and the requirement to effectively control and reduce the campus crime rate makes the need for seamless monitoring of campus monitoring more practical and urgent. High-definition (HD, 720P) and full HD (FULLHD, 1080P), compared to standard definition (D1, 720 × 576), the essential difference is that it can provide higher unit pixel DPI, which directly brings two As a result, HD cameras can provide clearer images and farther line of sight than standard-definition cameras with the same focal length lens. As shown in the figure above, at an imaging distance of 10 meters, if the SD camera can achieve a DPI of 250 PPM, the HD camera can achieve a DPI of 750 PPM or even higher. The actual sensory effect is as shown on the right, the image is more delicate, the color layer is richer, and the edge is sharper. So, at a greater distance, the HD camera can provide the same DPI as the SD camera, as shown below. That is to say, in the picture taken by the SD camera, if you want to view the remote details, and perform partial enlargement, the picture may be blurred and worthless; but at the same distance, the high-definition picture is partially enlarged, at least It can achieve the standard definition image quality and has the monitoring value, which actually realizes the practical electronic zoom function. In addition, the 720P/1080P screen ratio is different from the traditional SD D1/CIF 4:3, which is more suitable for the human eye's field of view 16:9, which can bring a broader monitoring field of view. In this way, the same distance clearer picture, the farther distance of the relatively clear picture, and the broader field of view than the standard definition bring a direct result. Under the same coverage requirements, the number of HD cameras can be deployed less than the standard definition camera. The number of deployments, when deploying the same number of cameras, the coverage area of ​​the HD system is much smaller than that of the SD system, which is more conducive to the ideal state of “seamless monitoringâ€. Recently, the relatively hot "4K Ultra HD Camera", although it has a greater improvement in definition and has a broader view, but it also has some unavoidable shortcomings: for example, the effect of nighttime low illumination is far less than the current 720P/1080P camera; the code stream is too large, which increases the cost of the network bandwidth and storage; the decoding of the wall is still not mature... so 4K is not only in the security campus monitoring, but also in other industries. Application requirements. Panoramic monitoring mode In the campus, there are often major events, and on-site real-time security control is required. The venues of these activities are often empty squares and playgrounds. The space span is wide and the coverage is difficult to monitor. If the 360° monitoring of the dome is used, the inherent blind spot monitoring problem of the dome is difficult to solve, especially the omnidirectional storage cannot be realized. Therefore, in the security monitoring situations that are necessary for retrospective evidence collection, it is often necessary to deploy multiple guns to meet the requirements. The construction of the empty site is large, and the poles, wiring, and power are taken up, which greatly increases the engineering cost. Moreover, multiple screens of multiple guns will cause the whole scene to be split. For the monitoring personnel to grasp the overall situation, and quickly judge the handling of emergency events, it is better to meet the needs of panoramic monitoring in open space. That is, multiple lenses + multiple sensors are used to splicing a panoramic image, but such cameras rarely have an outdoor version with strong environmental adaptability, and in order to increase integration, the lens generally cannot use a universal high-definition lens, and is rarely used. Telephoto, medium-focus lenses with large depth of field, and equipment costs are also very expensive. Therefore, this panoramic camera is more used for the monitoring of high-end halls, and is rarely used in places where there is actual demand such as schools. However, based on the idea of ​​multi-screen splicing, there is another method that is simpler and cheaper to implement, that is, a picture of a plurality of high-definition gun cameras is used to splicing a 180° high-definition panoramic picture. Because it is a universal gun, it can be equipped with a suitable universal HD lens, which ensures that the picture is not deformed, and can guarantee a considerable depth of field, achieving a large angle, a large depth of field, and true panoramic monitoring. The panoramic picture of the small square in the dormitory area in the middle of the above picture is composed of the following three 1080P images: since it is three 1080P@25fps image stitching, the actual resolution of the panorama can reach 5760×1080@25fps, ie 620 Tens of megapixels, much higher than the 3 million pixels of most panoramic cameras, especially due to the splicing of 25fps full-frame moving pictures, the smoothness of the picture can guarantee the full-frame moving picture of full-frame 25fps, instead of 2048×1536 of some panoramic cameras. @20fps or 4096×1536@8fps. Then, when the electronic zoom realizes partial enlargement of ePTZ, the effect closer to D1@25fps can be obtained, and the upper and lower rows of the first spliced ​​large image are the effects of ePTZ. If you use a high-definition fast dome camera, the camera's cloud mirror control and panoramic screen linkage, that is, where the click on the panoramic screen, the dome will quickly gather. Where the focus is located, the combination of optical zoom mechanical PTZ and electronic zoom ePTZ can provide a clearer picture and optimal panoramic monitoring effect. Through the three guns + one billiard machine, it can provide a perfect panoramic monitoring solution for the campus square and playground at a price far lower than that of the imported panoramic camera. At present, the panoramic splicing scheme of Yushi has some problems in the panoramic camera and the 4K ultra-high definition camera. It has not been well promoted on the campus, and it has been recognized by many users. System-wide performance pressure The above is basically the positive impact on the campus monitoring after the deployment of the high-definition system, but in fact, after the deployment of the high-definition system, the bandwidth of the front-end video stream is greatly increased, and the overall system brings huge performance. pressure. The traditional D1 code stream is basically 1.5Mbps, and the 720P transmission stream is the most Low is not less than 3Mbps, it is recommended not less than 4Mbps, and 1080P transmission stream is up to 6Mbps, 8Mbps is recommended. Such multiplied data streams first impact the existing traditional storage models. At present, many digital systems follow the deployment and usage habits of devices in the past. For example, the NVR can support high-definition storage devices. The device form still uses the form specifications of past DVR-like box devices, such as 16-channel HD support. Into, it supports up to 8 disk slots, and the current mainstream 2TB hard disk is used to calculate up to 16TB of storage capacity. If the 720P high-definition image is calculated by 4Mbps code stream, the NVR supporting 16-channel 720P HD can support the storage days as 22 days. If 16-channel 1080P HD is supported, According to the 8Mbps stream, the storage days are only 11 days. Therefore, the NVR device that uses the DVR specification is absolutely unable to meet the requirements of the campus monitoring use in the high-definition era. The use of large-capacity professional centralized storage devices seems to be a way to cure the symptoms, which can effectively reduce the number of storage devices, centralized management, and improve management efficiency. However, if massive storage is concentrated in the central computer room, it will bring unbearable pressure on the bandwidth of the central computer room. Fortunately, the IPSAN of professional IP storage devices can support IP reachability, data access, and management reachability. Therefore, the best solution for the storage mode of high-definition systems should be to distribute storage devices in several extension rooms to reduce storage bandwidth pressure and achieve Centralized management of the central computer room to improve management efficiency. This effectively disperses the pressure impact of the high-definition system deployment on the storage and load of the entire system. HD is a system solution that can be represented by a high-definition camera. Real HD monitoring requires HD from the entire monitoring system. Due to the multiplication of video information, it will inevitably bring greater impact on video coding, transmission and storage systems. High-definition will bring about the demand growth and technological changes in computing, transmission, exchange and storage in the entire industry chain. High-definition will also bring huge changes to campus monitoring. Hvac Filters,Hepa Air Filter,Hvac Air Filters,Hepa Media Filter Dongguan V1 Environmental Technology Co., Ltd. , https://www.v1airpurifier.com