As the camera moves from analog to network, "HD" has gradually become a hot spot for the market. Its appearance allows people to see more clearly and obtain more details. However, while the client can only see people's faces from now on and now can “see people’s facesâ€, it also puts forward another requirement that is to see more widely, that is, to see in the same scene. More things. In this regard, it was originally solved by using a few cameras to cover an area, or using a fast ball to cruise back and forth. But in some cases, these solutions can not fully meet the requirements of customers, such as customers need to determine the movement of people in the same picture, or need to use the things in the same scene to observe the problem to explain some problems, this time you need The panoramic camera, this article mainly discusses the development and application of the panoramic camera.
The development and status quo of panoramic camera
At present, there is no clear definition of a panoramic camera in the industry. For cameras that can see a wider range and have a larger angle, we all call it a panoramic camera. For example, a short focal length 5 megapixel camera installed in a plaza or at the gate can basically clear the gates or things on the square. Many people call this camera a panoramic camera. There are also some manufacturers that use 360-degree cameras combined with specific installation solutions called panoramic cameras. For example, a vertically-down fisheye camera is installed on the ceiling of a conference room. It is a panoramic camera.
At present, the product form of the fish-eye panoramic camera includes multi-lens, single fish-eye lens, and hybrid.
Single fisheye lens type: The use of a gun type camera or a dome type camera plus a fisheye lens, which is also the simplest and most economical way to achieve panoramic monitoring. The key point of this method is that the camera itself has a pair of fisheyes. "Distortion" correction capability, or can be combined with special processing software to correct the image after the fisheye lens distortion, and without leaving any traces into a normal image, so that the human eye can accept, this type of panoramic camera representative manufacturers Mobotix , odd and even, Dragon, Hikvision and Yin Hao, etc., this article focuses on the application of a single fish-eye lens panoramic camera.
Multi-lens type: Multi-lens and multi-angle monitoring of mosaic images to achieve 360-degree monitoring. This method is very complex and costly, but it is less troubled by the fish-eye distortion caused by the fisheye panoramic camera. Representative manufacturers of panoramic cameras include ArecontVision and AVIGILON.
Hybrid: The use of PTZ ball machine and fish-eye lens, this method is relatively rare, the camera can be used as a dome camera when rotating, when the dome lens and the fisheye lens coincide, can be used as a panoramic camera, this Axis-like representative camera manufacturers.
Application mode and characteristics of panoramic camera
At present, panoramic cameras are mainly used in open-air outdoor areas, such as road traffic, open-air plazas, residential buildings, and port terminals. The monitoring width of some locations even reaches over 100 meters. It is impossible to see the panoramic image at the same time. There is no energy to look at details such as faces and vehicle license plates. These occasions only need to install a fisheye camera at the high point to meet the panoramic monitoring in a place.
Compared with traditional surveillance cameras, the advantages of panoramic cameras include:
Wide viewing angle
A fisheye lens can take 360 ​​degree panoramic view, which can replace traditional multiple cameras: users only need a dedicated fisheye lens to directly view the entire space, and the surrounding images can be collected once to complete the blind spot completely.
cut costs
This 360-degree panoramic surveillance capability of the panoramic camera eliminates the need to install multiple cameras to cover the entire surveillance area, thereby saving camera hardware investment. The number of surveillance camera channels is greatly reduced, which can save the cost of supporting equipment, such as lenses, protective covers, wiring, power supply, video, display and other related accessories and equipment. It can also reduce the difficulty of construction wiring, save installation time, labor costs and follow-up maintenance costs .
Virtual PTZ Technology
Using virtual PTZ technology, you can zoom in or move the image area in the surveillance field of view. When you change direction and observe another image area, it will not emit any noise, and it is secretive and unobtrusive. Because there are no mechanical moving parts and no mechanized operation is required at any time, the panoramic camera will not suffer any wear and the product will be robust and long-life. The image distortion correction of the panoramic view can be performed on a plurality of image areas. Thus, unlike the mechanical PTZ camera, the panoramic camera can simultaneously observe and record a plurality of different areas.
The key technology of panoramic camera
Judging the performance of a panoramic camera is good or not about two things: First, how much of the field of view of the effective coverage, how clear the scene can be seen; Second, see the clarity of the scene pixel number. The key technologies of the panoramic camera include:
High-resolution implementation
The high-pixel products are not only the choice of the Sensor, but also the ISP's processing, coding and corresponding cooperation with the network are very important, and in the corresponding structure, process and other requirements, it is strictly several times more than the ordinary camera.
Fisheye correction correction accuracy
In the process of developing a circular image generated by a fish-eye camera as an ordinary tile image acceptable to the human eye, an anti-distortion and anti-distortion algorithm is very important. Because from the lens selection, it is necessary to analyze the curvature of the lens, the optical refraction circuit analysis, and the combination of translucency considerations in order to obtain a better image source, in order to achieve a large depth of field, high resolution, and around the screen. The resolution of the center must be balanced. For the development of the panoramic camera, in addition to the strict screening to ensure the high quality of the lens, a long-term and in-depth study has been made on the fisheye expansion algorithm. At present, the circular image generated by the fisheye lens has been effectively expanded and processed, and a tile image customed by the human eye has been obtained, and corresponding optimization has been performed on the basis of no distortion and distortion details, ensuring the overall image. Clear and accurate.
The development trend of panoramic camera
It has been more than a decade since the development of the panoramic camera, but the real promotion has only started in the past two years. Because of its high price, complicated image processing technology, and low resolution after image correction, the panoramic camera did not enter the public's life like any other ordinary camera, but was mainly located in the professional application market. Scene environment or where vertical installation is easy.
At present, the awareness of the market for panoramic cameras is not very high, and more manufacturers are advocating and guiding work. Its industry circles have not had much controversy or doubt about the technology of the panoramic camera, and personally believe that there is no need for too much debate on the definition of the panoramic camera. The key is to see whether the product can meet the needs of customers and whether to solve users. Specific issues. More and more customers will demand “see more and see more clearlyâ€, so the panoramic camera must have a large market.
Multi-technology integration is the main direction for the development of future panoramic cameras:
VMS support
The image processing of the panoramic camera requires the support of VMS (video management software), but since the current fisheye expansion algorithm is proprietary to the manufacturer, the VMS support range is very limited. How to implement the fish-eye unfolding algorithm to realize sharing and realize the unified standard interface is the direction that future equipment manufacturers and integrators need to work together.
Resolution
A great advantage of panoramic cameras over ordinary cameras lies in their large monitoring range. However, considering the resolution density, cameras with the same pixels will cause pixel dispersion and degradation when monitoring a larger area. This is due to the large scope of monitoring. When sharing the same size of an imaging chip with a conventional surveillance lens, it requires receiving multiple times of image information, which results in a decrease in the resolution of the screen. Therefore, only the quality of the monitoring image is not required. High or when using high resolution imaging devices. This explains why the picture quality of a 3 megapixel panoramic camera looks like CIF resolution. So for the panoramic camera, improving the screen resolution is an important research topic in the future.
Low illumination
Most of the panoramic cameras do not have ICR (Mechanical Infrared Filters), which makes their low-light effects difficult to satisfy. Because in the future development will pay more attention to the night-time effect of the panoramic camera, such as the use of ICR + infrared fill light or enhance the sensor's photographic performance to enhance the low-light effect.
Wide dynamic
Taking a fish-eye camera as an example, a fisheye lens with a 360-degree view angle is used to monitor the entire scene. Such a wide range of monitoring will inevitably lead to difficulty in handling the white balance and exposure of the panoramic camera. Because of this, it limits the application of panoramic cameras indoors. Resolving the wide dynamic effect of the panoramic camera can promote the application of the panoramic camera in the indoor environment in the future.
intelligent
How to liberate the manpower security of security is the development direction of intelligent analysis. In particular, the realization of intelligent analysis under the condition of no dead angle monitoring of the panoramic camera will definitely bring about better security applications.
The development and status quo of panoramic camera
At present, there is no clear definition of a panoramic camera in the industry. For cameras that can see a wider range and have a larger angle, we all call it a panoramic camera. For example, a short focal length 5 megapixel camera installed in a plaza or at the gate can basically clear the gates or things on the square. Many people call this camera a panoramic camera. There are also some manufacturers that use 360-degree cameras combined with specific installation solutions called panoramic cameras. For example, a vertically-down fisheye camera is installed on the ceiling of a conference room. It is a panoramic camera.
At present, the product form of the fish-eye panoramic camera includes multi-lens, single fish-eye lens, and hybrid.
Single fisheye lens type: The use of a gun type camera or a dome type camera plus a fisheye lens, which is also the simplest and most economical way to achieve panoramic monitoring. The key point of this method is that the camera itself has a pair of fisheyes. "Distortion" correction capability, or can be combined with special processing software to correct the image after the fisheye lens distortion, and without leaving any traces into a normal image, so that the human eye can accept, this type of panoramic camera representative manufacturers Mobotix , odd and even, Dragon, Hikvision and Yin Hao, etc., this article focuses on the application of a single fish-eye lens panoramic camera.
Multi-lens type: Multi-lens and multi-angle monitoring of mosaic images to achieve 360-degree monitoring. This method is very complex and costly, but it is less troubled by the fish-eye distortion caused by the fisheye panoramic camera. Representative manufacturers of panoramic cameras include ArecontVision and AVIGILON.
Hybrid: The use of PTZ ball machine and fish-eye lens, this method is relatively rare, the camera can be used as a dome camera when rotating, when the dome lens and the fisheye lens coincide, can be used as a panoramic camera, this Axis-like representative camera manufacturers.
Application mode and characteristics of panoramic camera
At present, panoramic cameras are mainly used in open-air outdoor areas, such as road traffic, open-air plazas, residential buildings, and port terminals. The monitoring width of some locations even reaches over 100 meters. It is impossible to see the panoramic image at the same time. There is no energy to look at details such as faces and vehicle license plates. These occasions only need to install a fisheye camera at the high point to meet the panoramic monitoring in a place.
Compared with traditional surveillance cameras, the advantages of panoramic cameras include:
Wide viewing angle
A fisheye lens can take 360 ​​degree panoramic view, which can replace traditional multiple cameras: users only need a dedicated fisheye lens to directly view the entire space, and the surrounding images can be collected once to complete the blind spot completely.
cut costs
This 360-degree panoramic surveillance capability of the panoramic camera eliminates the need to install multiple cameras to cover the entire surveillance area, thereby saving camera hardware investment. The number of surveillance camera channels is greatly reduced, which can save the cost of supporting equipment, such as lenses, protective covers, wiring, power supply, video, display and other related accessories and equipment. It can also reduce the difficulty of construction wiring, save installation time, labor costs and follow-up maintenance costs .
Virtual PTZ Technology
Using virtual PTZ technology, you can zoom in or move the image area in the surveillance field of view. When you change direction and observe another image area, it will not emit any noise, and it is secretive and unobtrusive. Because there are no mechanical moving parts and no mechanized operation is required at any time, the panoramic camera will not suffer any wear and the product will be robust and long-life. The image distortion correction of the panoramic view can be performed on a plurality of image areas. Thus, unlike the mechanical PTZ camera, the panoramic camera can simultaneously observe and record a plurality of different areas.
The key technology of panoramic camera
Judging the performance of a panoramic camera is good or not about two things: First, how much of the field of view of the effective coverage, how clear the scene can be seen; Second, see the clarity of the scene pixel number. The key technologies of the panoramic camera include:
High-resolution implementation
The high-pixel products are not only the choice of the Sensor, but also the ISP's processing, coding and corresponding cooperation with the network are very important, and in the corresponding structure, process and other requirements, it is strictly several times more than the ordinary camera.
Fisheye correction correction accuracy
In the process of developing a circular image generated by a fish-eye camera as an ordinary tile image acceptable to the human eye, an anti-distortion and anti-distortion algorithm is very important. Because from the lens selection, it is necessary to analyze the curvature of the lens, the optical refraction circuit analysis, and the combination of translucency considerations in order to obtain a better image source, in order to achieve a large depth of field, high resolution, and around the screen. The resolution of the center must be balanced. For the development of the panoramic camera, in addition to the strict screening to ensure the high quality of the lens, a long-term and in-depth study has been made on the fisheye expansion algorithm. At present, the circular image generated by the fisheye lens has been effectively expanded and processed, and a tile image customed by the human eye has been obtained, and corresponding optimization has been performed on the basis of no distortion and distortion details, ensuring the overall image. Clear and accurate.
The development trend of panoramic camera
It has been more than a decade since the development of the panoramic camera, but the real promotion has only started in the past two years. Because of its high price, complicated image processing technology, and low resolution after image correction, the panoramic camera did not enter the public's life like any other ordinary camera, but was mainly located in the professional application market. Scene environment or where vertical installation is easy.
At present, the awareness of the market for panoramic cameras is not very high, and more manufacturers are advocating and guiding work. Its industry circles have not had much controversy or doubt about the technology of the panoramic camera, and personally believe that there is no need for too much debate on the definition of the panoramic camera. The key is to see whether the product can meet the needs of customers and whether to solve users. Specific issues. More and more customers will demand “see more and see more clearlyâ€, so the panoramic camera must have a large market.
Multi-technology integration is the main direction for the development of future panoramic cameras:
VMS support
The image processing of the panoramic camera requires the support of VMS (video management software), but since the current fisheye expansion algorithm is proprietary to the manufacturer, the VMS support range is very limited. How to implement the fish-eye unfolding algorithm to realize sharing and realize the unified standard interface is the direction that future equipment manufacturers and integrators need to work together.
Resolution
A great advantage of panoramic cameras over ordinary cameras lies in their large monitoring range. However, considering the resolution density, cameras with the same pixels will cause pixel dispersion and degradation when monitoring a larger area. This is due to the large scope of monitoring. When sharing the same size of an imaging chip with a conventional surveillance lens, it requires receiving multiple times of image information, which results in a decrease in the resolution of the screen. Therefore, only the quality of the monitoring image is not required. High or when using high resolution imaging devices. This explains why the picture quality of a 3 megapixel panoramic camera looks like CIF resolution. So for the panoramic camera, improving the screen resolution is an important research topic in the future.
Low illumination
Most of the panoramic cameras do not have ICR (Mechanical Infrared Filters), which makes their low-light effects difficult to satisfy. Because in the future development will pay more attention to the night-time effect of the panoramic camera, such as the use of ICR + infrared fill light or enhance the sensor's photographic performance to enhance the low-light effect.
Wide dynamic
Taking a fish-eye camera as an example, a fisheye lens with a 360-degree view angle is used to monitor the entire scene. Such a wide range of monitoring will inevitably lead to difficulty in handling the white balance and exposure of the panoramic camera. Because of this, it limits the application of panoramic cameras indoors. Resolving the wide dynamic effect of the panoramic camera can promote the application of the panoramic camera in the indoor environment in the future.
intelligent
How to liberate the manpower security of security is the development direction of intelligent analysis. In particular, the realization of intelligent analysis under the condition of no dead angle monitoring of the panoramic camera will definitely bring about better security applications.
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