An Improved Retinex low-illumination image enhancement algorithm

Abstract

Low-illumination images are generally low-quality images. The retinex algorithm can cause halo artifacts and loss of details in processing. Therefore, an improved Retinex algorithm is proposed. Firstly, the HSI color space which is more in line with the human visual characteristics is selected instead of the RGB image, that is, the luminance component I is processed. Then, the illuminance image is estimated by using a guided filter that fuses the edge detection operator, and the edge detection operator can be better positioned. At the edge, an illuminance image with rich edge information can be obtained; after obtaining the illuminance image, the reflected image can be obtained by the Retinex principle, the obtained reflected image is subjected to low-rank decomposition, and the low-rank property of the image is used to suppress the enlarged halo and the enhancement process. Noise; finally, the visual effect is further improved by local contrast enhancement. Experiments show that the algorithm can effectively improve the brightness and contrast of the image, preserve the details of the image, and also suppress the noise interference in the enhancement process. The subjective visual effect and objective evaluation results of the image have also been greatly improved.