%A Ming-xing LIN %T Low-light image enhancement algorithm based on variational structure %0 Journal Article %D 2020 %J JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) %R 10.6040/j.issn.1671-9352.0.2020.202 %P 72-80 %V 55 %N 9 %U {http://lxbwk.njournal.sdu.edu.cn/CN/abstract/article_3335.shtml} %8 2020-09-20 %X

Aiming at the problem that the images captured under low illumination present some defects, such as low brightness and poor visibility, a low-light image enhancement algorithm based on variational structure guided filtering is proposed. First, the maximum of R, G and B channels are searched at each pixel of the input image, and the bright channel map is obtained by using the maximum filtering. Secondly, a novel guided filtering based on variational model is constructed to refine the bright channel image to estimate the illumination component. Subsequently, the reflection component is obtained by removing the illumination component according to the Retinex model. Finally, homomorphic filtering and linear stretching are employed to further improve the contrast of the reflection component to output an enhanced image with clear visibility. Comprehensive experimental results show that this algorithm can effectively and quickly enhance the illumination and contrast of low-light images and retain details.