Study Of Image Dehazing On The New Method Based On The Combination Of Dark Channel Prior And Retinex Algorithm

At present, the foggy image don’t meet the work of feature extraction and edge sharpening because the quality of the image with fog decrease. So the image dehazing technology help the staff process image in different applications. Since the birth of digital image technology, image dehazing technology has been developed for several years. There are many different defogging method based on different models and mathematical methods in these years.Image dehazing technology generally can be divided into two categories:image restoration based on physical model and image enhancement based on non physical model. Image restoration based on physical model (like the atmospheric scattering model) needs the parameters of the model. This method is more comprehensive account of the causes of degraded images. But this method spends so much because of processing relatively complex. Image enhancement based on non physical model process images only from the enhancement aspects. This method enhances image contrast and extract edge to recover the image without considering the causes of degraded images. This process based on the method is relatively simple and spend small time with using some algorithm or operators.This paper is based on the two kinds of method, puts forward a improved image dehazing method based on the physical model and digital enhancement combing the their advantages by using the dark channel prior based on physical model defogging technology and Retinex algorithm for image enhancement. The dark channel prior is based on the principle that the minimum gray value of three channels in image without fog closes to O.Then we can estimate roughly the transmittance according the dark channel prior and use Retinex algorithm to eliminate halo so that we can get the clear image.The main research contents of this paper include the following aspects:One, the foggy images are processed with the dark channel prior; Two, the images processed in the step one are enhanced based on Retinex algorithm due to the halo produced with rough transmittance in step one. Three, achieving the method above by using OPENCV,and processing many foggy images like UAV aerial images, maritime images, ordinary outdoor images.