基于模拟多曝光融合的低照度图像增强方法

Low-light image enhancement method based on simulating multi-exposure fusion

针对部分低照度图像整体亮度偏暗、对比度差和视觉信息偏弱等问题,提出一种基于模拟多曝光融合的低照度图像增强方法。首先,利用改进的变分Retinex模型和形态学的结合产生基准图来保证曝光图像集中的主体信息;其次,结合Sigmoid函数和伽马矫正构造新的光照补偿归一化函数,同时提出了一种基于高斯引导滤波的反锐化掩模算法,用于调整基准图的细节;最后,分别从亮度、色调和曝光率设计曝光图集的加权值,通过多尺度融合得到最终增强结果,有效地避免了增强结果中的光晕和颜色失真。在不同的公开数据集上的实验结果表明,与传统的低照度图像增强方法进行相比,所提方法降低了亮度失真率,提升了视觉信息保真度。该方法能够有效地保留视觉信息,有利于实现低照度图像增强的实时性应用。

Aiming at the problems of low luminance, low contrast and poor visual information, a low-light image enhancement method based on simulating multi-exposure fusion was proposed. Firstly, the improved variational Retinex model and morphology were combined to generate the reference map to ensure the subject information in the exposed image set. Then, a new illumination compensation normalization function was constructed by combining Sigmoid function and gamma correction. At the same time, an unsharp masking algorithm based on Gaussian guided filtering was proposed to adjust the details of the reference map. Finally, the weighted values of exposed image set were designed from luminance, chromatic information and exposure rate respectively, and the final enhancement result was obtained through multi-scale fusion with effective avoidance of halo phenomenon and color distortion. The experimental results on different public datasets show that, compared with the traditional low-light image enhancement method, the proposed method has reduced the lightness distortion rate and increased the visual information fidelity. The proposed method can effectively preserve visual information, which is conducive to the real-time application of low-light image enhancement.