A fusion algorithm is proposed for the restoration and enhancement of underwater images. Color balance, contrast optimization and histogram stretching are carried out. To alleviate the effect of color shift in an underwater image, the scalar values of R, G, B channels are renewed so that the distributions of the three channels in histogram are similar. Instead of refining the transmittance in dark channel prior based restoration, an optimized contrast algorithm is employed by which the optimal transmittance is determined. To further improve the brightness and contrast of underwater images, a histogram stretching algorithm based on the red channel is given. To verify the effectiveness of the proposed fusion algorithm, experimental underwater images are treated. Results show that the quality of underwater images is improved significantly, both in term of subjective visual effect and objective evaluation. The proposed underwater image processing strategy is also compared with some popular techniques. Comparison results indicate the advantage of the proposed strategy over others.

中文翻译：

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基于色彩平衡，对比度优化和直方图拉伸的融合算法的水下图像恢复和增强

提出了一种融合算法，用于水下图像的恢复和增强。进行色彩平衡，对比度优化和直方图拉伸。为了减轻水下图像中色移的影响，更新了R，G，B通道的标量值，以使直方图中三个通道的分布相似。代替在暗通道中基于先验的恢复来细化透射率，而是使用优化的对比度算法来确定最佳透射率。为了进一步提高水下图像的亮度和对比度，给出了一种基于红色通道的直方图拉伸算法。为了验证所提出的融合算法的有效性，对实验水下图像进行了处理。结果表明，水下图像的质量显着提高，无论是主观视觉效果还是客观评价。提出的水下图像处理策略也与一些流行的技术进行了比较。比较结果表明了该策略相对于其他策略的优势。