A Fog-removing Method of Colorized Images Based on HighPass Filtering
Zou Xing, Yu Liu, Xiaoling Tan, Huilong Liu · 2011
Fog may cause the impairment of image as well as the decrease in the distinguish ability. Traditional Retinex-based enhancement methods are easy to suffer the existence of halo artifacts whiling dealing with high dynamic range images, while the general one to filter the three RGB channels respectively would damage the relationship of the images. This paper aims to put forward an enhancement method of colorized images based on high pass filter. It firstly turns the image from RGB model to HIS model, Firstly, transfer the image brightness information to frequency by Fourier, and use high-pass filter to remove low-frequency information, and then transfer back to spatial using Fourier, next, use histogram equalization, and synthesize finally. This method can effectively avoid producing halo artifacts because of poor illumination and color distortion because of the destruction of the balance of color channel, and it also has the advantages of little computation, fast, and suits for hand-held devices after improved.