LightEnhancement Dataset LOL [0.485, 0.456, 0.406] for ImageNet 0.299R+0.587G+0.114*B=0.458971 set num size mean std low 485 (485, 400, 600, 3) [0.0629,0.0606,0.0558] [0.0430,0.0412,0.0425] high 485 (485, 400, 600, 3) [0.4717,0.4558,0.4379] [0.1830,0.1838,0.1915]