Visual Perception Enhancement Under Bad Condition And Its Application

Video or image captured by camera will suffer from the image blurring, weak contrast and color distortion by the influence of environmental factors, which will affect the further image analysis and processing seriously. Therefore, no matter in theory or application, it’s very important and valuable to improve the image quality by the image enhancement technologies.This paper proposed a solving algorithm for the unknown parameter of atmosphere scattering model after analyzing the principle of image deterioration in foggy weather and discussing the physical meaning of atmosphere scattering model. A depth estimation algorithm using edge constraint is given for promoting the dehaze. In addition, this paper also proposed an algorithm to evaluate the dehazed effect according to visible edges and image naturalness by syncretizing computer vision and human sensing. The paper focuses on the following sections:(1) Research and analysis on the atmosphere scattering mode as well as the principle of DCP. This section proposed a DCP extraction algorithm under the edge constraint against the shortcomings of existing DCP extraction algorithm, which improved the accuracy of DCP prior estimate and realized fast dehaze of foggy image. The experimental results show the validity and efficiency of the algorithm.(2) A depth estimation algorithm from forward motion video was given. We first extracted the foreground field by region segmentation and optimized the depth estimation of foreground filed for higher precision, and then applied the depth information to forward motion video for dehaze. The experimental results show the validity of the algorithm.(3) An improved dehaze evaluation mechanism based on visible edges was proposed against the shortcomings of existing dehaze evaluation methods, and the image naturalness also had been syncretized as an evaluating indicator. We not only focus on the objective indicator of image enhancement, but also take the naturalness of human’s visual perception into account. The experimental results from large image dataset proved that the proposed mechanism can evaluate the effectiveness of the dehaze algorithm objectively and allsidedly.