BRIUIE: A Bio-Retina Inspired Underwater Image Enhancement Framework

The dim shooting environment and light scattering and absorption frequently result in degraded underwater images. The images are characterized by uneven brightness, low contrast, color deterioration, and blurred details. Existing underwater image enhancement methods excel in full-reference and non-reference metrics, yet may fail to align with human visual tendencies. To make the restored images more consistent with natural visual effects, an underwater image enhancement framework named BRIUIE is proposed. BRIUIE draws inspiration from the morphology and functions of various cell layers in the vertebrate retina. Following the visual transmission mechanisms of retinal signals, image brightness is balanced by simulating the feedback and dynamic regulation processes of horizontal cells in response to illumination variation. Meanwhile, simulating the center-surround receptive fields of bipolar and ganglion cells and implementing the color opponent mechanism effectively mitigate color distortion and low contrast. The designed multi-scale feature fusion module facilitates the complementary advantage of the ON and OFF visual pathways of ganglion cells, employing a contrastive learning strategy to prevent overfitting because of simple consistency loss. Comprehensive full-/non-reference experiments demonstrate the proposed BRIUIE outperforms other SOTA methods in quantitative evaluations, while also delivering qualitative results that closely align with human visual assessment standards.