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.

水下拍摄的图像通常会遭受偏色，并且由于光线在水中传播时会被散射和吸收，因此可见度较低。在本文中，我们提出了一种颜色校正和双间隔对比度增强的新方法，以提高水下图像的质量。首先，采用一种基于子间隔线性变换的简单有效的色彩校正方法来解决色彩失真问题。然后，将高斯低通滤波器应用于L通道，以分解低频分量和高频分量。最后，基于最佳均衡阈值策略和S形函数的Bi-interval直方图增强低频和高频分量，以增强图像对比度并突出显示图像细节。受多尺度融合的启发，我们采用了简单的线性融合方法来集成增强的高频和低频分量。与最新方法的比较表明，该方法可输出高质量的水下图像，并具有良好的定性和定量评估。