Structure–texture decomposition-based dehazing of a single image with large sky area

Traditional dehazing methods based on restoration are prone to color distortion and noise amplification when dealing with hazy image with large sky area. To improve dehazing effect, we propose a dehazing algorithm based on image structure–texture decomposition and reconstruction. Hazy image is decomposed into high-frequency texture layer and low-frequency structure layer by total variation. Discrete cosine transform is used to generate an image mask to separate sky area and non-sky area. The texture layer is denoised by the mask, and the structure layer is dehazed by dark channel prior. The media transmission is corrected by color attenuation prior. Finally, the denoised texture layer and the dehazed structure layer are reconstructed to obtain the dehazed image. A no-reference image quality assessment is also proposed to evaluate the dehazed images. Experiment results show that, compared with the state-of-the-art methods, our algorithm has better dehazing effect on non-sky area, and the sky area after dehazing is smooth without color distortion and noise.