Optical Defog Cameras

One of the new problems in recent years is the emergence of smog. The haze brings a severe test to the video surveillance system, which is mainly manifested in several aspects: the reflected light on the surface of the object is attenuated due to the scattering of atmospheric particles, resulting in the image of the object. The image brightness becomes weaker and the image color becomes darker; the reflected light participates in the imaging of other pixels through the forward scattering of atmospheric particles, resulting in blurred images and reduced resolution; some atmospheric particles have large particle sizes, which become noise during the imaging process, and the image appears Rough point distribution; natural light that has nothing to do with imaging is scattered by atmospheric particles and enters the image sensor to participate in imaging, resulting in image saturation, reduced contrast, and hue shift, and the details of some important targets are more difficult to.

A generation of fog penetration technology-optical fog penetration technology. Ordinary visible light cannot penetrate clouds and smoke, but near-infrared rays can penetrate a certain concentration of mist and smoke. The camera needs to be processed according to different wavelengths to achieve the purpose of focusing. At the same time, the camera needs to be redesigned. Imagine the invisible light of this frequency. Since this invisible light has no corresponding visible light color map, the rendered image is black and white. Shooting objects through clouds, fog, and water vapor is equivalent to using a dual lens (water droplets and real lens). In addition to the R light can be correctly focused on the CCD imaging surface, the GB in the RGB light cannot be normally projected on the CCD imaging surface, which prevents the normal mode lens from obtaining a normal and clear image from the cloud and humidity.

Fog-permeable lens refers to a lens that has a high transmittance to long-wavelength light (700nm-950nm) in the infrared light field and has the function of controlling the long-wavelength light imaging surface (camera CCD target surface). This lens is used in combination with a high-performance day and night camera. Even in visible light (color image) environments such as fog, dust, smoke, and light rain, ordinary lenses can only get blurred images. Under harsh conditions, the effective observation distance is greatly shortened. It can also shoot very clear, high-contrast black and white images to improve the effect of long-distance observation. Using the principle of near-infrared light diffracting small particles, using near-infrared light filters, coating technology and electronic image enhancement technology to penetrate mist in foggy days. The monitoring distance reaches more than 1.5 times the visibility, and there is no blind spot for remote security monitoring all-weather.

Optical fog uses the principle of near-infrared rays to diffract tiny particles to achieve precise and rapid focusing. The key to this technology is the lens and filter. Through physical means, the principle of optical imaging is used to improve the clarity of the image. The disadvantage is that only black and white surveillance images can be obtained.