Abstract:When dealing with low illumination images, the traditional Retinex algorithm can improve the image recognition, but there are some shortcomings, such as "halo artifacts" and the lack of image details. In this paper, a new image enhancement algorithm, which combines the guided filtering image hierarchical processing with multi-scale Retinex algorithm, is adopted. Firstly, in the HSI color space, the original image is divided into detail image and basic image by using the guide filter algorithm. Then, gain coefficients are constructed for the two separated image layers, which are respectively enhanced and reconstructed to obtain a new brightness image. Finally, the new brightness image is restored in the RGB color space to output the final image with higher brightness and better restoration. Experimental results show that the algorithm makes the edges and details of the image more prominent, and can eliminate the "halo artifact" phenomenon. Moreover, the objective evaluation index has also been greatly improved.