Research And Realization Of Image Sharpening Method In Haze Day

Along with the rapid development of China's modernization level,communication technology,computer internet technology,television broadcasting technology,image processing technology and other computer vision technology is becoming more and more widely used in people's life.However outdoor image acquisition devices(such as road monitoring,video cameras and remote sensing satellite imaging)are easily affected by fog,haze,smoke,dust and other bad weather,resulting in serious color distortion and the decrease of image sharpness and contrast and so on,thus can not meet the requirements of human vision.Especially in recent years,the haze weather is getting worse in China.It is of great practical significance to study image sharpening method in haze days in order to reduce the impact of equipment by bad weather and guarantee the system's normal work.an improved image sharpening method in haze day is presented in this paper that based on the deep study about the algorithms which based on image enhancement and physical model.The main research contents of this paper are as follows:(1)In the aspect of image enhancement based on increasing contrast,we mainly study careful the global histogram equal ization,CLAHE,Retinex algorithm and summarize the advantages and disadvantages.In order to solve this problem that using Retinex algorithm to process haze images would cause time-consuming and color distortion,we propose an improved method of converting color space.Firstly,it turns the original color image from RGB into HSV color space,secondly the Retinex algorithm is only performed on the brightness component V,then modify saturation component accordingly and color component H remain constant Finally,we get clear images.The experimental results show that the improved algorithm can effectively promote color fidelity and reduce the time complexity.(2)In the aspect of image restoration based on atmospheric scattering model,we mainly study and summarize the theory and the process of implementing and advantages and disadvantages.Aiming at the problem of poor real-time ability and poor processing effect of DCP algorithm,this paper suggests a new method based on image segmentation.Firstly,it uses the k-means algorithm to divide the haze image into two parts of the sky background and the target.Secondly,we estimate the atmospheric light value A in the segmented sky part,so it avoids the interference of white objects and increases the accuracy.Then,as to optimize transmission rate,we use bilateral filter algorithm which can preserve the edges and details effectively.Finally,we restore the clear image of no fog.The experimental results show that the improved algorithm can greatly increase the real time and effectively solve the problem of color distortion in the sky part of image and keep the edge details in image well.(3)According to the research of this paper,we realized a rapid software that based on OpenCV and MFC to process sharpness of the foggy images,which makes the image sharpening quick and easy and display directly.