Design And Development Of Vehicle Monitoring Terminal In Foggy Environment

Under the environment of the fog, road is in low visibility, the drivers are going to run into trouble, for example collision, hitting, a traffic accident, even danger of lives and so on, because can’t see clearly people, animals, other small obstacles on the road ahead in the process of the vehicle. At this time, a kind of auxiliary driving will be helpful, it is very necessary to configure the vehicle monitoring terminal of the fog environment for vehicles. The vehicle monitoring terminal of the fog environment provides driving help for drivers, when driving in foggy weather conditions and in the road ahead appears small obstacles, the driver don’t know whether can go through directly, the driver can confirm by looking at the monitoring terminal, if it is obstacle, the driver should make measures immediately to better drive and avoid an accident, and if not, can move forward. But as we all known, under the environment of the fog, movies and images captured by the vehicle monitoring terminal are blurred, with the decrease of contrast and low resolution, result in which videos and images that offer to the driver are not clear or images information are inaccurate, make drivers have inaccurate judgment, so unable to achieve very good effect of auxiliary driving, on the contrary it could lead to accidents. Videos and images defogging technology can improve the fog weather’s degraded image; let the vehicle monitoring terminal obtain clear videos and images; assist effectively drivers to drive safely.With the degradation question of videos and images under the fog environment, this paper studies firstly the effect mechanism of fog on the image imaging and image imaging principle under the fog environment, next deals the road or traffic foggy videos and images with two methods of image enhancement and image restoration, eliminates the influence of fog on the video image, recoveries scenarios color and contrast, then gets clear videos and images. In this paper, from two aspects of image enhancement and image restoration algorithms, explore suitable videos and images defogging algorithms for hardware environment. Research on the influence mechanism of fog on the videos and images, deduce the image restoration model on the basis of incident light attenuation model and atmospheric optical participating in imaging model, lucubrate the histogram equalization algorithm based on image enhancement and Retinex fogging algorithm; and the dark-channel prior theory defogging algorithm based on image restoration. Use dark-channel value of the fog environment’s images to estimate transmittance; Obtain 0.1% pixels of the highest brightness value in the dark-channel image, these pixels correspond to the original image, in the original image the maximum brightness value is the estimate value of atmospheric optical. And then according to image imaging model restore clear image. Comparative analysis of the transmittance images of rough estimate, refined by soft Matting, refined and smoothed by bilateral filter, obtain better transmittance image with better smoothed, refined, and edge effect, which is used to restore more clear image. The above experiments are verified by using road videos and images in life in Matlab2014 a environment.With embedded Linux operating system, ARM11 processor, OK6410 development board for experimental platform, build development platform of the vehicle monitoring terminal under the fog environment. Build cross-compilation environment of host machine and the target board, realize the transplantation of embedded Linux operating system to the development board, including the transplantation of boot loader, kernel, file system; Research camera interface of development board and CMOS image sensor, and finally realize the collection, capturing, showing, saving, processing of videos and images, including processing part is to realize defogging for the vehicle monitoring terminal foggy videos and images.