Brief analysis: Multi-technology integration paves the way for the future of panoramic cameras

At present, panoramic cameras are mainly used in outdoor places with wide fields of view, such as road traffic, open squares, residential buildings, ports and docks, etc. The monitoring width of some places even reaches more than 100 meters. While seeing the panoramic image clearly to realize dispatching, it is impossible and there is no energy to see the details such as faces and vehicle license plates. In these occasions, only one fisheye camera needs to be installed at a commanding height to meet the panoramic monitoring of a place. As the application scope of panoramic cameras gradually expands, the market prospects are also gradually broadening.

Panoramic camera application features

Panoramic cameras have been developed for more than ten years, but the real promotion has only started in the past two years. Due to its high price, complex image processing technology and low resolution after image correction, panoramic cameras have not entered the lives of the general public like other ordinary cameras, but are mainly positioned in the professional application market, such as large scene environments or occasions that are easy to install vertically. Compared with traditional surveillance cameras, the advantages of panoramic cameras include:

Ultra-wide monitoring viewing angle: A fisheye lens can capture a 360-degree panoramic view and can replace multiple traditional cameras: users only need a dedicated fisheye lens to directly view the entire space, and the surrounding images can be seen at once, completely eliminating blind spots.

Reduce costs: The 360-degree real-time panoramic monitoring capability of panoramic cameras eliminates the need to install multiple cameras to cover the entire monitoring area, thus saving camera hardware investment. The number of surveillance cameras is greatly reduced, which can save the cost of supporting equipment, such as lenses, protective covers, wiring, power supplies, recording, display and other corresponding accessories and equipment, and can also reduce the difficulty of construction wiring, save installation time, labor costs and subsequent maintenance costs.

Virtual PTZ technology: With virtual PTZ technology, the image area within the monitoring field of view can be enlarged or moved. When changing direction to observe another image area, no noise will be made, which is stealthy and difficult to detect. Since there are no mechanical moving parts and no need for mechanical operation all the time, the panoramic camera will not be worn out. The product is strong and durable, and its service life is greatly extended. The image distortion correction of the panoramic view can be performed on multiple image areas. In this way, unlike the mechanical PTZ camera, the panoramic camera can observe and record multiple different areas at the same time.

Broad market prospects

The advantage of panoramic cameras is that they can achieve the most efficient monitoring effect with the least amount of equipment, which means that they can reduce the construction costs of shields, wiring and personnel, and can reduce the cost of monitoring projects. However, after all, they have been developed for a short time (five years) and have disadvantages that cannot be ignored, such as the high unit price of cameras, the lack of breakthroughs in monitoring distance, and problems such as image storage and restoration, which urgently need to be adjusted and improved.

At present, the market awareness of panoramic cameras is not very high, and more manufacturers are doing publicity and guidance. In fact, there is not much controversy or doubt about the technology of panoramic cameras in the industry, and I personally think that there is no need to debate too much about the definition of panoramic cameras. The key is to see whether the product can meet the needs of customers and solve the specific problems of users. More and more customers will ask to "see more and see more clearly", so panoramic cameras will inevitably have a large market.

Four key technologies of panoramic cameras

First, the quality of the lens will greatly affect the quality of the surveillance image; a good lens can reach high definition and more than one million pixels, and the higher the frame rate (the speed of animation transmission per second), the clearer the movement process and detailed movements of the monitored target can be seen.

Second, a good panoramic camera must have a high-resolution image sensor. Since the panoramic camera has a wide monitoring range, the image sensor must have a huge amount of information, unlike ordinary cameras that only need to process part of the monitoring scene. Therefore, the resolution of the image sensor is also the key to whether the image is clear after the monitoring image is magnified.

Third, the imaging principle of panoramic cameras using fisheye lenses is different from that of ordinary cameras. The edge of the image often forms a convex and deformed picture, so it is easier to distort or distort the image than ordinary cameras, affecting the image quality. Therefore, how to correct and restore the image and see the monitored object in the image clearly is the most important issue for panoramic cameras.

Theoretically, there are two ways to correct the problem of fisheye lens distortion. One is to process information and restore the image by the back-end platform; the other is to directly correct it in the camera's built-in software and then transmit it to the monitoring back-end. Generally speaking, it is recommended to use the latter to solve the problem of fisheye lens distortion, which can relieve the pressure of network transmission bandwidth and back-end storage, and improve the efficiency of monitoring operation.

Fourth, you can use virtual PTZ to zoom in and out on the stored images for detailed observation. In the field of security monitoring, PTZ controls the pan/tilt and tilt and the lens focus, and is used to automatically or manually track the locked target, and follow the target all the way within the monitoring range. The virtual PTZ used by panoramic cameras has a similar application concept to the tracking effect of the pan/tilt, but it does not need to perform actual mechanical rotation like a real pan/tilt. Instead, it achieves a similar effect by zooming the image, which can greatly increase the service life of the monitoring system, making it easier for monitoring personnel to operate and reducing maintenance costs.

Future development is moving towards multi-technology integration

VMS support: The image processing of panoramic cameras requires the support of VMS (video management software), but since the current fisheye expansion algorithms are proprietary to the manufacturers, the scope of VMS support is very limited. How to achieve interoperability and sharing of fisheye expansion algorithms and achieve a unified standard interface is the direction that equipment manufacturers and integrators need to work together in the future.

Resolution: A big advantage of panoramic cameras over ordinary cameras is their large monitoring range. However, from the perspective of resolution density, cameras with the same pixels will cause pixel dispersion and degradation when monitoring a larger area. This is because the monitoring range is very large, and the imaging chip of the same size as the traditional monitoring lens needs to receive several times the image information, which causes the image resolution to decrease. Therefore, it can only be used when the quality of the monitoring image is not too high or when a high-resolution imaging device is used. This explains why the image quality of a 3-megapixel panoramic camera looks like CIF resolution. Therefore, for panoramic cameras, improving the image resolution is an important research topic in the future.

Low illumination: Most panoramic cameras do not have ICR (mechanical infrared filter), which makes it difficult to achieve satisfactory low illumination effects. In the future, more attention will be paid to the night effect of panoramic cameras, such as using ICR infrared fill light or improving the photosensitivity of the photoreceptor to improve the low illumination effect.

Wide dynamic range: Take fisheye cameras as an example. They use fisheye lenses with a 360-degree ultra-wide viewing angle to monitor the entire scene. Such a large-scale monitoring will inevitably lead to difficulties in the processing of white balance and exposure of panoramic cameras. It is precisely because of this that the application of panoramic cameras in indoor environments is limited. Solving the wide dynamic range of panoramic cameras can promote the application of panoramic cameras in indoor environments in the future.

Intelligence: How to liberate the manpower of security is always the development direction of intelligent analysis. Especially under the condition of no-blind-angle monitoring by panoramic cameras, realizing intelligent analysis will definitely bring better security applications.

About panoramic camera:

Panoramic cameras, as the name implies, are camera products that can monitor a large scene, monitor the entire process, and shoot from all angles. It has been more than five years since the first product was officially launched on the market. Generally speaking, there are two ways to achieve a panoramic effect: one is to use a fisheye lens (wide-angle lens); the other is to use multiple lenses in a camera to achieve it.

Regardless of the method used, the so-called global monitoring, that is, the camera is in a stationary state (without the need for pan/tilt assistance), and can perform 180-degree (mounted on the wall) or 360-degree (mounted on the ceiling) monitoring.

When monitoring, the camera can achieve uninterrupted shooting of the same large scene without switching the screen, solving the problem of incoherent images when ordinary cameras monitor from all directions, and making the work of monitoring personnel more convenient.