改进的伽马校正与多尺度融合的水下图像增强

由于光在水下传播会发生吸收和散射,导致采集 的水下图像出现模糊、对比度低、色偏、光照不 均匀等问题。针对以上问题,提出了一种改进的伽马校正与多尺度融合的水下图像增强算法 。首先基于G 通道对R和B通道进行补偿,并对RGB 三通道进行直方图拉伸后使用灰度世界(Gray World) 算法得到颜 色校正图像；然后使用改进的伽马函数改善颜色校正后图像光照不均匀问题,得到光照均匀 图像,并进 行归一化处理；再对光照均匀图像使用限制对比度的自适应直方图均衡化(contrast limite d adaptive histogram equalization,CLAHE)算法得到对比度提升图像；最后采用多尺度融 合算法对以上得出的3幅图 片进行融合,得出增强图像。实验结果表明,提出的算法对不同水下环境的图像均有较好的处理 效果,图像质量评价指标得到明显提高。

Underwater image enhancement based on improved Gamma correction and multi-scale fusion

As the absorption and scattering of light in underwater propagation,p roblems such as fuzzy,low contrast,color deviation and uneven illumination appear in underwate r images taken.In view of the above problems,an improved underwater enhancement algorithm based on Gamma correction and multi-scale fusion is proposed.Firstly,Red and Blue channels a re compensated based on Green channel,and the correction image is obtained by Gray World algorithm after histogram stretching of RGB three channels.Then,the color corrected image is corrected f or uneven illumination by using the improved Gamma function to obtain the uneven illuminat ion corrected image,and the illumination uniformity image is normalized.Then,the contrast of t he image after uneven illumination correction is improved by contrast limited adaptive histogra m equalization (CLAHE) algorithm to obtain the contrast improved image.Finally,the multi-scale fusio n algorithm is used to fuse the above three images to obtain the enhanced image.Experimental results s how that the proposed algorithm has good processing effects on images in different underwater environments,and the image quality evaluation index is significantly improved.