基于虚拟曝光方法的单幅逆光图像增强

Single Backlit Image Enhancement Based on Virtual Exposure Method

逆光图像目标区域可视质量低、背景区域过度曝光,是影响图像质量的重要因素之一。针对现有的逆光图像增强方法在增强暗区细节信息时不能很好地抑制明亮区域过度增强的问题,提出了一种基于虚拟曝光的单幅逆光图像增强方法。首先,引入虚拟曝光图像,并根据参数确定最佳低曝光图像和高曝光图像;然后,使用非线性亮度增强方法和基于邻域相关对比度增强方法分别处理暗区和亮区;最后,采用拉普拉斯金字塔融合方法将暗区、亮区的细节和特征融合。使用自然图像和合成图像对所提方法进行实验,结果表明所提方法具有更少的颜色和亮度失真,视觉效果更加自然。

The visual quality of backlit image in target area is low and its background area is overexposed,which are important factors affecting image quality.Aiming at the problem that the existing backlit image enhancement methods cannot suppress the excessive enhancement of bright areas while enhancing the detail information of dark areas well,a single backlit image enhancement method based on virtual exposure is proposed in this paper.First,the virtual exposure image is introduced,and the best low-exposure image and high-exposure image are determined according to parameters.Then,the dark and bright areas are processed by nonlinear enhancement method and the neighborhood correlation method respectively.Finally,the details and features of the dark and bright areas are fused by Laplacian pyramid fusion method.Experiments results based on natural images and synthetic images show that the proposed method has less color and brightness distortion,and the visual effect is more natural.