The quality of visual information of underwater images is mainly limited by selective absorption and scattering in water. Usually, most researches of underwater image recovery focus on addressing the scattering via inverting an optical model, but less on compensating for the unbalance attenuation caused by the selective absorption. For this reason, the recovery results are still subject to artifacts and color shifting. In this letter, a parameter-adaptive compensation method is proposed to mitigate the selective absorption. Different from the fixed parameter utilized compensation operations, the proposed method utilizes an adaptation parameter to compensate the attenuation. Further, a rigorous gradient relation between the dominant color channel and the compensated channel is established to avoid over-compensation or under-compensation. The final recovery results show the parameter-adaptive compensation method is beneficial to improve the visual quality and the Underwater Image Quality Measurement (UIQM) scores of recovered underwater images.

中文翻译：

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用于处理水下选择性吸收的参数自适应补偿 (PAC)

水下图像视觉信息的质量主要受水中选择性吸收和散射的限制。通常，水下图像恢复的研究主要集中在通过反演光学模型来解决散射问题，而较少关注由选择性吸收引起的不平衡衰减。出于这个原因，恢复结果仍然受到伪影和颜色偏移的影响。在这封信中，提出了一种参数自适应补偿方法来减轻选择性吸收。与固定参数利用补偿操作不同，所提出的方法利用自适应参数来补偿衰减。此外，在主色通道和补偿通道之间建立严格的梯度关系以避免过度补偿或补偿不足。