Dual-Purpose Method for Underwater and Low-Light Image Enhancement via Image Layer Separation

Underwater and low-light images possess different characteristics; hence, few approaches have been exploited to jointly improve the visibility of these images. Herein, a dual-purpose method that achieves satisfactory performance in enhancing the visibility of both underwater and low-light images is proposed. In our study, the formation of these two types of images is described in a unified manner. Subsequently, an objective function is formulated, and several novel regularization terms are imposed on our optimization algorithm to separate incident light and reflectance as well as suppress intensive noise simultaneously. Next, post-processing algorithms are implemented to correct the color distortion of the incident light and improve the contrast of the reflectance. Ultimately, an enhanced image with clear visibility and natural appearance can be achieved by integrating the processed reflectance and incident light. Additionally, comprehensive tests were performed to compare the proposed method with other outstanding methods. Experiments on images captured in various scenes demonstrated the effectiveness of the proposed method, as evident in enhanced underwater and low-light images.