Multi-wavelength polarization characteristic constraints for underwater image clarification.

Abstract

To enhance the recovery performance of underwater image clarification algorithms based on polarization technology in scattering underwater environments, a multi-wavelength polarization constrained underwater image clarification method is proposed. This method takes into account the varying polarization characteristics across different wavelengths. The image is processed by separating it into three RGB color channels (red, green, and blue). Initially, the Stokes vectors of the backscattered light for each of the three channels are individually analyzed. From this analysis, a pair of orthogonally polarized images with identical backscatter intensity is derived for each color channel. Next, the histograms of these orthogonally polarized image pairs are stretched, ensuring that the polarization relationship between them is preserved. Finally, polarization differencing is applied to the orthogonally polarized images in each channel, which are then converted into grayscale images to achieve improved image clarity. The effectiveness of the proposed method has been validated through a series of polarization de-scattering experiments conducted in water with varying turbidity levels. These experiments demonstrate the method's superior performance in image restoration, particularly in scenarios with high polarization characteristics when compared to other similar approaches.