基于Lab色彩空间和色调映射的彩色图像增强算法

摘要

针对低照度图像对比度增强处理中的细节保留和色彩恒常问题,提出一种新颖的基于Lab色彩空间和色调映射的Retinex图像对比增强算法.首先,在Lab色彩空间中将一个低对比度的输入图像分解成亮度和色度分量,并使用自适应双边滤波估计照明的强度,以便根据亮度和颜色值来考虑合适的相邻像素.然后利用基于抛物线的色调映射函数来提高估计光照图像的对比度.最后,将加强的亮度和原始的色度结合在一起以产生一个增强的彩色输出图像.实验结果表明,所提算法通过减弱图像伪影增强了图像的细节和边缘结构,同时通过避免色彩偏移较好地保留了图像的自然度.%According to the detail preserving and color constancy problems in the low illumination image enhancement processing,this paper proposed a novel Retinex enhancement algorithm based on Lab color space and color mapping image contrast.Firstly,the input image of Lab color space with a low contrast is decomposed into luminance and chrominance components,and adaptive bilateral filtering is used for estimation of illumination intensity,so that appropriate adjacent pixels can be considered according to the brightness and color values.Then the tone mapping function based on the parabola is used to improve the contrast of the estimation of illumination image.Finally,the enhanced brightness and the original chroma are combined together to produce an enhanced color output image Experimental results show that the proposed algorithm can enhance the image details and edge structure by reducing the image artifacts,and can preserve the image's nature by avoiding the color shift.