Bioinspired Polarized Optical Flow Enables Turbid Underwater Target Motion Estimation

Underwater target motion estimation is a challenge for ocean military and scientific research. In this work, we propose a method based on the combination of polarization imaging and optical flow for turbid underwater target detection. Polarization imaging can reduce the influence of backscattered light and obtain high-quality images underwater. The optical flow shows the motion and structural information of the target. We use polarized optical flow to obtain the optical flow field and estimate the target motion. The experimental results of different targets under varying water turbidity levels illustrate that our method is realizable and robust. The precision is verified by comparing the results with the precise displacement data and calculating two error measures. The proposed method based on polarized optical flow can obtain accurate displacement information and a good recognition effect. Moving target segmentation based on the Otsu method further proves the superiority of the polarized optical flow under turbid water. This study is valuable for target detection and motion estimation in scattering environments.