The role of fog camera in fog days is doubtful. Haikang fog cameras have long been recognized by users. Nowadays, the introduction of high-definition fog cameras has benefited greatly from the fog-clear high-definition electric lens, but the camera itself The fog-transparent principle has also made great progress in the near-end time.
Fog Camera 1. Fog-transmitting principle of the fog camera The natural light is composed of light waves with different wavelengths. The visible range of the human eye is approximately 390nm-780nm. The wavelengths from long to short correspond to the seven colors of red orange blue green orange purple respectively. Of these, wavelengths less than 390 nm are called ultraviolet rays, and wavelengths greater than 780 nm are called infrared rays. The small particles in the air, such as fog and smoke, block the light and make the light unable to pass. Therefore, the eyes of people who can only receive visible light cannot see the back of the smoke and fog. The longer the wavelength is, the stronger the diffraction ability is, that is, the stronger the ability to bypass the obstacle, and the infrared light has a relatively long wavelength and is less affected by the aerosol during the propagation, and can pass through a certain concentration of fog and dust to achieve accurate focusing. This is the basis of optical fogging.
To achieve the three elements of fog:
In the range of invisible light, light with a frequency can penetrate the fog, but due to the different wavelengths, it needs to be processed on the camera to achieve the purpose of focusing on it. At the same time, it needs to be redesigned on the camera. The invisible light at this frequency is imaged. Since this invisible light has no corresponding visible light color map, the image presented on the monitor is black and white.
(1) Lens with chromatic aberration compensation For better fogging effects, the design of the lens is critical. In order to ensure that the visible light imaging system can obtain ideal images before and after the fog penetration, the lens must ensure high transmittance in the visible and near-infrared bands, and the color difference is modified during the two band switching process to ensure that the switching does not need to be performed after switching. Adjust the focus.
The center wavelength of the normal lens transmission spectrum is between 500 and 600m. The lens in the fog-through system needs high transmittance at 500-600nm and 780-900nm, so the lens adopts a multi-layer coating technology. The transmittance of the 500 to 900 wavelength range of the lens is greater than 80%. In principle, the wider the near-infrared wavelength band that can be used, the better, but it is limited by the difficulty of designing the optical path of the lens and the CCD's photosensitivity. Currently, the longest infrared band available in the security industry is known to be 1100 nm.
(2) CCD with high near-IR sensitivity
High-sensitivity CCD cameras with good frequency response from the visible to the near-infrared range are necessary for an excellent system, so that only one camera can be used to achieve the visible and near-red bands by transforming the filters. Separately used, in order to facilitate the use of visible light band to improve the clarity of the image and use the ability of the near-infrared band to penetrate the mist to increase the viewing distance.
(3) Black Level Stretching Image Processing Scattering of water vapor and solid particles over the ocean and over the air creates visible, dark, and white light at distances far away. Long-distance imaging can't go beyond visibility. Filters Use has undoubtedly played a significant role, but to achieve people's vision for the longer distance, the better the distance, the better the use requirements. Electronic processing techniques must be used to further filter out this gray-white interference signal that is caused by scattering and then process the useful white or black-and-white signal to obtain an excellent image signal for a distant object.
Second, the fogging technology is mainly divided into four types:
A. Optical fogging General visible light cannot penetrate clouds and smoke, but near-infrared rays can penetrate a certain concentration of fog and dust. Optical fogging can use the principle of near-infrared rays to diffract tiny particles and achieve accurate and fast focusing. The key to technology is mainly in the lens and filter. Through physical means, using the principle of optical imaging to enhance the clarity of the picture. The disadvantage is that you can only get black and white monitor pictures.
B algorithm fog penetration algorithm fog penetration technology, also known as video image anti-reflection technology, generally refers to the fog and water vapor dust and other unclear images become clear, emphasizing some of the features of the image, inhibited The characteristics of interest make the quality of the image improved and the amount of information enhanced.
C photoelectric fogging photoelectric fogging is the combination of the above two functions, through the movement of the integration through the embedded FPGA chip and ISP / DSP operation processing to achieve color picture output. On the one hand, the fogging technology can distinguish between distant scenes, close shots, fog and other factors. Selecting the fog level can achieve the best regional effect, which is different from the overall improvement of the picture contrast in the past without delay. On the other hand, the high-speed operation of the chip will produce noise points, and the effect is particularly prominent when the nighttime illumination is insufficient. Therefore, the CCD sensor and the large aperture lens are generally required for the integrated movement to achieve a good low-light effect. It is the best technology for fogging on the market.
D Dummy fog This is mainly through the artificial adjustment of contrast, sharpness, saturation, brightness and other values, or do some filter switching device, so that the image highlights, thereby improving the subjective visual effects. The disadvantage is that the scenery cannot be refocused and it is difficult to satisfy the visual experience.
With the development of industry and its impact on the climate, haze has increasingly become a common weather phenomenon, which has a great impact on the picture quality of outdoor application monitoring systems. The defogging technology can improve the quality of video surveillance from multiple perspectives, can be used for fog treatment in various foggy weather conditions, can significantly enhance the contrast of images, make images transparent and clear, and can significantly enhance the details of images. Information, so that the original details of the hidden images are fully displayed; can enhance the saturation of the image, so that the image is vivid, lively and vivid, the image after the fog treatment to maintain accurate hue, natural appearance, and thus get a good image quality With visual experience.
Fog Camera 1. Fog-transmitting principle of the fog camera The natural light is composed of light waves with different wavelengths. The visible range of the human eye is approximately 390nm-780nm. The wavelengths from long to short correspond to the seven colors of red orange blue green orange purple respectively. Of these, wavelengths less than 390 nm are called ultraviolet rays, and wavelengths greater than 780 nm are called infrared rays. The small particles in the air, such as fog and smoke, block the light and make the light unable to pass. Therefore, the eyes of people who can only receive visible light cannot see the back of the smoke and fog. The longer the wavelength is, the stronger the diffraction ability is, that is, the stronger the ability to bypass the obstacle, and the infrared light has a relatively long wavelength and is less affected by the aerosol during the propagation, and can pass through a certain concentration of fog and dust to achieve accurate focusing. This is the basis of optical fogging.
To achieve the three elements of fog:
In the range of invisible light, light with a frequency can penetrate the fog, but due to the different wavelengths, it needs to be processed on the camera to achieve the purpose of focusing on it. At the same time, it needs to be redesigned on the camera. The invisible light at this frequency is imaged. Since this invisible light has no corresponding visible light color map, the image presented on the monitor is black and white.
(1) Lens with chromatic aberration compensation For better fogging effects, the design of the lens is critical. In order to ensure that the visible light imaging system can obtain ideal images before and after the fog penetration, the lens must ensure high transmittance in the visible and near-infrared bands, and the color difference is modified during the two band switching process to ensure that the switching does not need to be performed after switching. Adjust the focus.
The center wavelength of the normal lens transmission spectrum is between 500 and 600m. The lens in the fog-through system needs high transmittance at 500-600nm and 780-900nm, so the lens adopts a multi-layer coating technology. The transmittance of the 500 to 900 wavelength range of the lens is greater than 80%. In principle, the wider the near-infrared wavelength band that can be used, the better, but it is limited by the difficulty of designing the optical path of the lens and the CCD's photosensitivity. Currently, the longest infrared band available in the security industry is known to be 1100 nm.
(2) CCD with high near-IR sensitivity
High-sensitivity CCD cameras with good frequency response from the visible to the near-infrared range are necessary for an excellent system, so that only one camera can be used to achieve the visible and near-red bands by transforming the filters. Separately used, in order to facilitate the use of visible light band to improve the clarity of the image and use the ability of the near-infrared band to penetrate the mist to increase the viewing distance.
(3) Black Level Stretching Image Processing Scattering of water vapor and solid particles over the ocean and over the air creates visible, dark, and white light at distances far away. Long-distance imaging can't go beyond visibility. Filters Use has undoubtedly played a significant role, but to achieve people's vision for the longer distance, the better the distance, the better the use requirements. Electronic processing techniques must be used to further filter out this gray-white interference signal that is caused by scattering and then process the useful white or black-and-white signal to obtain an excellent image signal for a distant object.
Second, the fogging technology is mainly divided into four types:
A. Optical fogging General visible light cannot penetrate clouds and smoke, but near-infrared rays can penetrate a certain concentration of fog and dust. Optical fogging can use the principle of near-infrared rays to diffract tiny particles and achieve accurate and fast focusing. The key to technology is mainly in the lens and filter. Through physical means, using the principle of optical imaging to enhance the clarity of the picture. The disadvantage is that you can only get black and white monitor pictures.
B algorithm fog penetration algorithm fog penetration technology, also known as video image anti-reflection technology, generally refers to the fog and water vapor dust and other unclear images become clear, emphasizing some of the features of the image, inhibited The characteristics of interest make the quality of the image improved and the amount of information enhanced.
C photoelectric fogging photoelectric fogging is the combination of the above two functions, through the movement of the integration through the embedded FPGA chip and ISP / DSP operation processing to achieve color picture output. On the one hand, the fogging technology can distinguish between distant scenes, close shots, fog and other factors. Selecting the fog level can achieve the best regional effect, which is different from the overall improvement of the picture contrast in the past without delay. On the other hand, the high-speed operation of the chip will produce noise points, and the effect is particularly prominent when the nighttime illumination is insufficient. Therefore, the CCD sensor and the large aperture lens are generally required for the integrated movement to achieve a good low-light effect. It is the best technology for fogging on the market.
D Dummy fog This is mainly through the artificial adjustment of contrast, sharpness, saturation, brightness and other values, or do some filter switching device, so that the image highlights, thereby improving the subjective visual effects. The disadvantage is that the scenery cannot be refocused and it is difficult to satisfy the visual experience.
With the development of industry and its impact on the climate, haze has increasingly become a common weather phenomenon, which has a great impact on the picture quality of outdoor application monitoring systems. The defogging technology can improve the quality of video surveillance from multiple perspectives, can be used for fog treatment in various foggy weather conditions, can significantly enhance the contrast of images, make images transparent and clear, and can significantly enhance the details of images. Information, so that the original details of the hidden images are fully displayed; can enhance the saturation of the image, so that the image is vivid, lively and vivid, the image after the fog treatment to maintain accurate hue, natural appearance, and thus get a good image quality With visual experience.
Greenhouse Film Electric Roll Up
The Greenhouse Film Manual Roll Up Unit can roll up a length of 60-80 meter, running stably with fine out side looking and long time of usage. The inside drive gears are made of high quality steel with fine workmanship, and what is more, there is lubricating bearing assembled on the out put and input shaft. At the meantime, there is also a group of reverse gear added to it. All these make the unit to be light and easy for
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