I. Introduction
Low-light images often have low visibility that does not satisfy the human eye’s perception requirements. Among the tasks in the field of computer vision, low-light image enhancement (LLIE) is a fundamental and important branch that aims to improve the visibility of an image and is a technique for reconstructing and enhancing the illumination of an image under low-light conditions [1]. This technique not only helps humans better observe and understand visual scenes but also helps downstream tasks better capture rich visual information in unpredictable and complex scenarios, such as facial recognition [2], image segmentation [3], object detection [4], [5] infrared and visible image fusion [6], [7] and 3D reconstruction [8]. However, as photos captured under certain low-light conditions inevitably introduce undesirable noise, artefacts, loss of image details and visual degradation, LLIE becomes extremely challenging.