Enhancing underwater image via color correction and Bi-interval contrast enhancement

• Published in: Signal processing. Image communication Vol. 90; p. 116030
• Main Authors: Zhang, Weidong, Dong, Lili, Zhang, Tong, Xu, Wenhai
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.2021; Elsevier BV
• Subjects: Color; Color correction; Contrast enhancement; Enhancing details; Equalization; Histograms; Image contrast; Image enhancement; Image quality; Linear transformations; Low pass filters; Low visibility; Underwater; Underwater image enhancement; Enhancing details; Underwater image enhancement; Contrast enhancement; Color correction
• ISSN: 0923-5965; 1879-2677
• DOI: 10.1016/j.image.2020.116030

Underwater captured images often suffer from color cast and low visibility due to light is scattered and absorbed while it traveling in water. In this paper, we proposed a novel method of color correction and Bi-interval contrast enhancement to improve the quality of underwater images. Firstly, a simple and effective color correction method based on sub-interval linear transformation is employed to address color distortion. Then, a Gaussian low-pass filter is applied to the L channel to decompose the low- and high-frequency components. Finally, the low- and high-frequency components are enhanced by Bi-interval histogram based on optimal equalization threshold strategy and S-shaped function to enhancement image contrast and highlight image details. Inspired by the multi-scale fusion, we employed a simple linear fusion to integrate the enhanced high- and low-frequency components. Comparison with state-of-the-art methods show that the proposed method outputs high-quality underwater images with qualitative and quantitative evaluation well.