Image Enhancement Method for Smart Grid Visual Monitoring System

In the field of video surveillance in the smart grid, monitoring room staff are faced with the problem of being unable to see low or excessive illumination areas clearly due to diverse lighting conditions in the monitoring scene. To allow them to observe more image details, it is necessary to increase the contrast of these areas and improve the visibility of the images. This paper proposes a method to enhance uncertain illumination images. Our solution is to decompose the image by filtering to enhance the details, and adjust the brightness with an adaptive scheme. First, the Guide Filter (GF) is used to decompose the input image into a base layer and a detail layer. After filtering, the detail layer is stretched by the arctan function and adjusted by the light intensity of the base layer, and then the adjustment result is linearly combined with the base layer. Finally, the brightness is adjusted by using the adaptive curve guided by "maximum entropy" to improve the contrast in low illumination areas and excessive illumination areas. Experimental results show that this algorithm can significantly improve the quality of images with uneven illumination, more details in low illumination areas and excessive illumination areas can be observed, and it has the advantage of lower running time consumption over some popular algorithms.