基于人工欠曝光融合和白平衡技术的水下图像增强算法

Underwater image enhancement algorithm based on artificial under-exposure fusion and white-balancing technique

获得清晰准确的水下图像是人类探索水下世界的重要前置条件。然而与平常图像相比,水下图像往往具有对比度低、细节保留不足及颜色失真等问题,这导致其视觉效果不佳。针对上述问题,提出了基于人工欠曝光融合和白平衡技术(AUF+WB)的水下图像增强算法。首先,利用调节伽马值的方式对原始水下图像进行操作,从而生成5幅相应的欠曝光图像;然后,以对比度、饱和度及良好曝光度作为融合权重,并结合多尺度融合来生成融合图像;最后,将各类颜色通道补偿后的图像分别结合灰色世界假设白平衡生成相应的白平衡图像,再利用水下彩色图像质量评价指标(UCIQE)及水下图像质量评价标准(UIQM)对得到的白平衡图像进行评价。通过选取不同类型的水下图像作为实验样本,将AUF+WB算法与现存先进的水下图像去雾算法进行比较,结果表明AUF+WB算法在图像质量定性、定量两方面分析中和对比算法相比均有更好的表现。所提出的AUF+WB算法可矫正水下图像的颜色失真,并增强其对比度、恢复其细节,有效提升了水下图像的视觉质量。

Acquisition of clear and accurate underwater images is an important prerequisite to help people explore the underwater world.However,compared with regular images,underwater images always have problems such as low contrast,detail loss and color distortion,resulting in bad visual effect.In order to solve the problems,a new underwater image enhancement algorithm based on Artificial Under-exposure Fusion and White-Balancing technique(AUF+WB)was proposed.Firstly,the Gamma correction operation was used to process the original underwater image and generate 5 corresponding under-exposure images.Then,the contrast,saturation and well-exposedness were employed as fusion weights,and the multi-scale fusion method was combined to generate the fused image.Finally,the images compensated by various color channels were combined with the Gray-World white balance assumption respectively to generate the corresponding white balance images,and these obtained white balance images were evaluated by using the Underwater Color Image Quality Evaluation(UCIQE)and the Underwater Image Quality Measure(UIQM).With selecting different types of underwater images as experimental samples,the proposed AUF+WB algorithm was compared with the existing state-of-the-art underwater image defogging algorithms.The results show that,the proposed AUF+WB algorithm has better performance than the comparison algorithms on both qualitative and quantitative analysis of image quality.The proposed AUF+WB algorithm can effectively improve the visual quality of underwater images by removing color distortion,enhancing contrast,and recovering details of underwater images.