Research On The Single Image Defogging Algorithm Based On Weighted Guided Filtering And Adaptive Tolerance

In recent years,with the development of industry and urbanization in China,haze weather appears frequently.The image acquired by the image acquisition equipment under such bad conditions usually has the problems of low definition,low signal-to-noise ratio and loss of key information of the image,which seriously affects the performance of outdoor vision system.In recent years,using effective methods to achieve image defogging has become the focus of research.Based on the atmospheric scattering model,this paper analyzes the causes of image degradation in foggy days,introduces the principle of image defogging based on the dark channel priori in detail,and proposes two new image defogging algorithms based on the dark channel priori in view of the defects of the dark channel priori image defogging.The main work of this paper is as follows:(1)An improved weighted guided filtering image defogging algorithm based on Laplacian of bilateral(LOB operator)is proposed.In view of the fact that the traditional guided filter can not adapt to the texture characteristics of different regions of the image itself,which may lead to the halo artifacts in some edge regions of the restored image,this paper designs an edge perception weight function of LOB operator,which is incorporated into the guided filter to form a weighted guided filter.The simulation results show that the improved weighted guided filter can effectively avoid the halo artifacts at the edge of the defog image.(2)A single image defogging algorithm based on adaptive tolerance is proposed.In view of the defect that dark channel prior is not suitable for bright areas such as sky,this paper proposes a calculation method of adaptive tolerance based on the characteristics of fog image itself,and then uses the tolerance to correct the transmittance of dark channel prior failure area and obtain the final restored image.The simulation results show that the improved algorithm can not only recover the image with large bright area,avoid color distortion,but also save the details of the image better.Finally,through subjective observation and objective index analysis,the proposed algorithm is better than the original algorithm.In addition,compared with some advanced algorithms,the image processing effect of the algorithm proposed in this paper is better.