Minmin Yang, Jianchang Liu, Zhengguo Li, Shubin Tan, Pre-processing for single image dehazing, Signal Processing: Image Communication, Volume 83, 2020, 115777, ISSN 0923-5965, https://doi.org/10.1016/j.image.2019.115777.
Existing single image haze removal algorithms could suffer from noise amplification in sky regions and
possible color distortion in restored images due to noise in haze images. In this paper, a simple pre-processing
tool is introduced for single image haze removal so as to reduce the effect of noise in the restored image. The
input image is first decomposed into base and detail layers by using a weighted guided image filter (WGIF).
The airlight and transmission map are estimated from the base layer. In order to restore the objects close
to the camera well, the decomposition of haze image is adaptive to the value of the transmission map. If
the transmission map of a pixel is small, it is decomposed into two layers, otherwise, not decomposed. Since
the noise is included in the detail layer, the base layer is amplified in the final image if the haze image is
decomposed. Experiments show that the proposed pre-processing tool can indeed be applied to improve the
state-of-the-art haze removal algorithms.