Experimental results of imaging objects in turbid liquid integrating multiview circularly polarized speckle images and deconvolution method

Abstract

We hereby suggest and experimentally demonstrated an approach to enhance image quality during recovery of objects hidden in turbid liquid by fusion of single-shot multi-view circularly polarized speckle images collected by lens array and deconvolution algorithm based multiple medium sub-PSFs viewpoints. Circular polarized light was used since it has superior polarization memory enable deeper probing within turbid media. Experiments were carried out in transmission mode upon targets (transmitted and opaque) of different geometric shapes embedded within turbid liquid media of commercial instant coffee blended in lukewarm water at varied concentrations. The media were illuminated by circular polarized laser beam and multiple circular polarized speckled images were captured by camera. To counter the effect of scattering noises, multiple object images and Wiener deconvolution algorithm based multiple medium PSFs acquisition were shifted to a common center and then fused together to yield reconstructed images of the hidden objects. Following experiments, we demonstrated that by fusion of multiple images a better reconstruction was obtained as compared to the use of a single imaging lens. For a quantitative comparison, some common image quality metrics were used to evaluate the reconstruction quality. In addition, a phase only filter was applied during the deconvolution and its performance was compared with Wiener filtering. Overall, the feasibility of the proposed technique is proven by the experimental results. This work can be beneficial for application to imaging hidden targets buried in turbid system such as biological medium, fog, smoke, rain, etc. and therefore has potential for a wide variety of applications in medical diagnostics, security, sensing, underwater imaging, and more.