Underwater Image Enhancement Based on Polarization Imaging

Abstract

Abstract. The need of high-quality underwater imaging is obviously required in many underwater applications. For example, underwater archaeology, underwater ecological research, underwater object detection and tracking. This paper presents a joint enhancing and denoising scheme for an image taken in underwater conditions. Conventional image enhancing methods may amplify the noise depending on the distance and density of the particles in the water. To suppress the noise and improve the enhancement performance, an imaging model is modified by adding the process of amplifying the noise in underwater conditions. This model offers depth-chromaticity compensation regularization for the transmission map and chromaticity-depth compensation regularization for enhancing the image. The proposed iterative underwater image enhancing method with polarization uses these two joint regularization schemes and the relationship between the transmission map and enhanced irradiance image. The transmission map and irradiance image are used to promote each other. To verify the effectiveness of the algorithm, polarizing images of different scenes in different conditions are collected. Different algorithms are applied to the original images. Experimental results demonstrate that the proposed scheme increases visibility in extreme conditions without amplifying the noise.

Pola4All: survey of polarimetric applications and an open-source toolkit to analyze polarization

“…Based on the active cross-polarization technique and an optimized version of the dark channel prior, they achieve contrast improvement for underwater imaging, with a single snapshot in real-time. Shen and Zhao 34 developed an iterative pipeline to jointly improve the image contrast and denoise the image. With two polarization images taken with a rotative filter at 0 deg and 90 deg, they compute the transmittance and the irradiance maps in underwater conditions for each color channel.…”