Rapid nighttime haze removal with color-gray layer decomposition

Nighttime haze usually reduces the visible distance and visual contrast of the nighttime scene. To resolve this problem, a color-gray layer decomposition method is presented to decompose a real-world image into color-world and gray-world layers in the RGB color space. Based on the presented layer decomposition, a new nighttime dehazing framework is proposed to remove glowing color, enhance illumination, and remove haze. Specifically, to correct nighttime hazy images, an effective glow decomposition approach is present to remove glowing color in the color-world layer. For low-light nighttime hazy scenes, gamma correction is applied to enhance illumination in the gray-world layer. After nighttime hazy image correction, to further refine the coarse estimation of the transmission and the atmospheric light, a relative weighted guided image filter is devised with a new relative edge-aware weighting. Additionally, a 2D atmospheric scattering model is established to well remove haze with the decomposed transmission and the fused local atmospheric light. Therefore, the proposed method can rapidly recover high-quality nighttime dehazing results and preserve the intrinsic color of the scene while avoiding color artifacts. Quantitative comparisons verify that the proposed nighttime dehazing framework can achieve excellent performance in nighttime haze removal against previous state-of-the-art methods.