*Article* **Efficient Traffic Video Dehazing Using Adaptive Dark Channel Prior and Spatial–Temporal Correlations**

#### **Tianyang Dong, Guoqing Zhao, Jiamin Wu, Yang Ye and Ying Shen \***

College of Computer Science and Technology, Zhejiang University of Technology, Hangzhou 310023, China; dty@zjut.edu.cn (T.D.); m15695719625@163.com (G.Z.); hzwujiamin@163.com (J.W.); yeyang80@zjut.edu.cn (Y.Y.)

**\*** Correspondence: shenying@zjut.edu.cn

Received: 6 March 2019; Accepted: 26 March 2019; Published: 2 April 2019

**Abstract:** In order to restore traffic videos with different degrees of haziness in a real-time and adaptive manner, this paper presents an efficient traffic video dehazing method using adaptive dark channel prior and spatial-temporal correlations. This method uses a haziness flag to measure the degree of haziness in images based on dark channel prior. Then, it gets the adaptive initial transmission value by establishing the relationship between the image contrast and haziness flag. In addition, this method takes advantage of the spatial and temporal correlations among traffic videos to speed up the dehazing process and optimize the block structure of restored videos. Extensive experimental results show that the proposed method has superior haze removing and color balancing capabilities for the images with different degrees of haze, and it can restore the degraded videos in real time. Our method can restore the video with a resolution of 720 × 592 at about 57 frames per second, nearly four times faster than dark-channel-prior-based method and one time faster than image-contrast-enhanced method.

**Keywords:** image dehazing; traffic video dehazing; dark channel prior; spatial-temporal correlation; contrast enhancement
