Abstract:The effect of target recognition and tracking will be affected by non-uniform low light image.In order to enhance the non-uniform low light image, This paper proposes an adaptive brightness layer image enhancement algorithm based on Retinex theory. First, isolate the I-layer image in HSI model are extracted and separated; Then use the Retinex theory and the multi-scale guided filter to obtain the illumination component of the I-layer. Automatically obtain the adjustment parameter k according to the average value of the input image, and adaptively adjust the brightness of the illumination component; Finally, according to the principal features analysis (PCA), the detail features of the two images are extracted and fused. Comparative experiments show that the algorithm can effectively improve the overall brightness and detail information of non-uniform low-illuminance images, while reducing the effects of uneven illuminance.