Image dehazing with uneven illumination prior by dense residual channel attention network

Abstract

Existing dehazing methods based on convolutional neural networks estimate the transmission map by treating channel-wise features equally, which lacks flexibility in handling different types of haze information, leading to the poor representational ability of the network. Besides, the scene lights are predicted by an even illumination prior which does not work for a real situation. To solve these problems, the authors propose a dense residual channel attention network (DRCAN) for estimating the transmission map and use an image segmentation strategy to predict scene lights. Specifically, DRCAN is built based on the proposed dense residual block (DRB) and dense residual channel attention block (DRCAB). DRB extracts the hierarchical features with increasing receptive fields. DRCAB makes the network focus on the features containing heavy haze information. After the transmission map is estimated, fuzzy partition entropy combined with graph cuts is used to segment the transmission map into scene regions covered with varying scene lights. This strategy not only considers the fuzzy intensities of the low-contrast transmission map but also takes spatial correlation into account. Finally, a clear image is obtained by the transmission map and varying scene lights. Extensive experiments demonstrate that our method is comparable to most of existing methods.