Underwater active polarization descattering based on a single polarized image

Abstract

Active polarization imaging techniques have tremendous potential for a variety of underwater applications. However, multiple polarization images as input are necessary for almost all methods, thereby limiting the range of applicable scenarios. In this paper, via taking full advantage of the polarization feature of target reflective light, the cross-polarized backscatter image is reconstructed via introducing an exponential function for the first time, only based on mapping relations of co-polarized image. Compared with rotating the polarizer, the result performs a more uniform and continuous distribution of grayscale. Furthermore, the relationship of degree of polarization (DOP) between the whole scene and backscattered light is established. This leads to an accurate estimation of backscattered noise and high-contrast restored images. Besides, single-input greatly simplifies the experimental process and upgrades efficiency. Experimental results demonstrate the advancement of the proposed method for objects with high polarization under various turbidities.

High-throughput microplastic assessment using polarization holographic imaging

“…However, there are still complex situations for MP analysis. For instance, multiple scattering and absorption exist in real seawater samples that are usually mixed with a lot of impurities, affecting the imaging effect 63 . Tracking and detecting MPs in cases of complicated turbid water scattering is our next focus of work 64 , 65 .…”

Snapshot Polarization-Sensitive Holography for Detecting Microplastics in Turbid Water

“…MP samples, as well as other natural particles, are suspended in pure water or milk solutions to simulate turbid aquatic environments. It is a common strategy to adjust the scattering effect by controlling the concentration of milk solutions. , A series of milk solutions with gradually increased concentrations are employed in this work. The scattering effect of the media is quantified using the concept of optical depth .…”

“…It is a common strategy to adjust the scattering effect by controlling the concentration of milk solutions. 40,41 A series of milk solutions with gradually increased concentrations are employed in this work. The scattering effect of the media is quantified using the concept of optical depth.…”

Underwater AUV Navigation Dataset in Natural Scenarios

“…The collection of pertinent data necessitates the utilization of shore-based platforms or motherships, and in intricate environments, human divers are also employed to facilitate navigation, thereby resulting in substantial costs. The range of underwater sensors is limited by the environment, especially in visible light, where active light sources are subject to forward and backward scattering [15]. Acoustic-based forward-looking sonar and side-scan sonar (SSS) are widely used for underwater environment sensing and terrain-matching navigation [16].…”