Adaptive structural compensation enhancement based on multi-scale illumination estimation

In real-world scenes, lighting conditions are often variable and uncontrollable, such as non-uniform lighting, low lighting, and overexposure. These uncontrolled lighting conditions can degrade image quality and visibility. However, the majority of existing image enhancement techniques are typically designed for specific lighting conditions. Consequently, when applied to images in uncontrolled lighting, these techniques are prone to result in insufficient visibility, distortion, overexposure, and even information loss. In this paper, to address the limitations of existing methods, we introduce an innovative and effective method for enhancing uncontrolled lighting images through adaptive structural compensation. Firstly, a joint filtering algorithm for illumination estimation is developed to effectively mitigate texture, edge and noise interference during illumination estimation. Secondly, we developed a multi-scale illumination estimation algorithm for the purpose of constructing a structural compensation map. This map is then used to control brightness compensation for different areas of the image. Finally, a two-stage compensation fusion strategy is designed to adaptively reconstruct the brightness distribution and effectively improve image visibility. Extensive experimental results indicate that our method outperforms some state-of-the-art approaches in improving the quality and visibility of images under uncontrolled lighting conditions.