The Long Range Optical Defog Zoom Camera Module

There are two types of defog technology for  long range zoom camea module.
Optical defog
Generally, 770~390nm visible light can not pass through the fog, however, Infrared can pass through the fog, because infrared has a longer wavelength than visible light, with a more obviously diffraction effect. This principle is applied in optical defog, and based on special lens and filter, so that the sensor can sense near-infrared(780~1000nm), and improve the picture clarity from the source by optically.
But because infrared is non-visible light, it is beyond the scope of the image processing chip, so only black and white image can be obtained.


E-defog
Electronic defog is the use of image processing algorithms to enhance the image. There are multiple implementations of electronic-defog.
For example, non-model algorithms are used to enhance image contrast, thereby improving subjective visual perception. In addition, there is a model-based image restoration method, which studies the causes of the illumination model and image degradation, models the degradation process, and uses inverse processing to eventually restore the image. The electronic-defog effect is significant, because in many cases the reason for the hazy phenomenon of the image is related to the resolution of the lens itself and the image processing algorithm in addition to the fog.
The development of defog technology
As early as 2012, the block zoom camera module SC120 launched by Hitachi has the function of defog. Soon, Sony, Dahua, Hivision, etc. also launched similar products with electronic-defog. After several years of development, the electronic-defog technology has gradually matured. In recent years, Lens manufacturers have in-depth cooperation with camera manufacturers, and have successively launched a variety of optical defog zoom camera block camera module .
Solution by View Sheen
View Sheen has launched a series of zoom camera module equipped with standard super defog (optical defog + electronic defog).  The optical + electronic method is used to optimize from the optical source to the back-end ISP processing. The optical source must allow as much infrared light as possible to pass through, so a large aperture lens, a large sensor and a filter with good anti-reflection effect must be considered comprehensively. The algorithm must be based on factors such as the distance of object and the intensity of fog, and select the level of defog, reduce the noise caused by image processing.

 

 

 


Post time: Dec-22-2020