A Variation-Based Nighttime Image Dehazing Flow With a Physically Valid Illumination Estimator and a Luminance-Guided Coloring Model
Journal
IEEE Access
Journal Volume
10
Pages
50153-50166
Date Issued
2022
Author(s)
Abstract
Image quality is often reduced in hazy weather, especially during the nighttime when image visibility can be further degraded. In this paper, we propose a robust variation-based nighttime image dehazing flow with a physically valid illumination estimator, a luminance-guided coloring model, and a transmission refinement procedure to effectively address this problem. We design a new illumination model to better address the non-global air-light issue in nighttime scenes. Then, we introduce a structure-preserving optimization flow based on Retinex theory to obtain ambient illumination. Color consistency is guaranteed because we use the input image as the initial guess of illumination in our coloring model. A variational procedure is developed to smoothen the estimated transmission map, where the block effect and the halos can be eliminated through the procedure. The proposed luminance-based correction mechanism further improves visual image quality in the presence of a large sky region. Our experiments are implemented based on actual hazy images. The user study indicates that the proposed method can effectively provide color consistency, preserve details, and reduce halo artifacts and noise in the resulting images compared to other state-of-the-art algorithms. When tested on real-world nighttime haze images, our dehazing flow quantitatively achieves 3.06 for NIQE and 2.99 for NR-CDIQA. © 2013 IEEE.
Subjects
alternating direction method of multipliers (ADMM); Image enhancement and restoration; nighttime image dehazing
Other Subjects
Color; Demulsification; Image enhancement; Image quality; Image reconstruction; Luminance; Structural optimization; Alternating direction method of multiplier; Alternating directions method of multipliers; Atmospheric modeling; Color consistency; Colored noise; Dehazing; Illumination models; Image color analysis; Nighttime image dehazing; Robust variation; Light sources
Type
journal article