Resolution enhancement in active underwater polarization imaging with modulation transfer function analysis

Abstract

Active polarization imaging technology is a convenient and promising method for imaging in a scattering medium such as fog and turbid water. However, few studies have investigated the influence of polarization on the resolution in underwater imaging. This paper reports on the effects of polarization detection on the resolution of underwater imaging by using active polarization imaging technology. An experimental system is designed to determine the influence under various polarization and water conditions. The modulation transfer function is introduced to estimate the resolution variations at different spatial frequencies. Results show that orthogonal detection supplies the best resolution compared with other polarization directions in the turbid water. The performance of the circular polarization method is better than the linear process. However, if the light propagates under low scattering conditions, such as imaging in clean water or at small optical thickness, the resolution enhancement is not sensitive to the polarization angles.

Time-of-Flight Imaging in Fog Using Polarization Phasor Imaging

“… Finally, we establish a polarization phasor imaging model for recovering amplitude and depth images in the foggy scenes by estimating the scattering component. Optical polarimetric defogging is a powerful method to enhance visibility in fog, which uses the difference of polarization properties between the reflected and scattered light [32]. It can be divided into passive polarization defogging [33][34][35][36] and active polarization defogging [37][38][39][40][41], with good performance in visibility enhancement for RGB images.…”

Image quality, meteorological optical range, and fog particulate number evaluation using the Sandia National Laboratories fog chamber

“…[1][2][3][4][5][6] Other studies have examined the effect of wavelength on light penetration through dispersive media. [7][8][9] Simulations have been utilized to examine foundational aspects of photon propagation through scattering media, [10][11][12][13][14] but these studies often assume model parameters such as monodispersed droplet size and homogeneous atmospheric conditions. 1,15 Validating models and measuring performance degradations typically involve field testing within naturally occurring fog.…”