Abstract

Light transport in turbid media results in multiple complex interactions between light and matter. Specifically, as light travels in such media, it is absorbed and dispersed at each differential step, which translates in a loss of visibility through that medium. Seeing through tissues is one of the main goals in the field of medical imaging as in the field of computational imaging. However, due to the loss of coherence of the illumination, it is an uttermost complex task. The recently introduced Phasor Fields provides a new theoretical framework inside the field of non-line-of-sight imaging that deals with the reconstruction of geometry hidden from the field of view. It makes use of the temporal information of light transport obtained by means of transient imaging techniques. The level of reconstructions reached by this method, managing to reconstruct scenes of a complexity until now impossible, allows theorizing about its use in a scenario even more complicated as it would be to see through turbid media.

In this work, we extend Phasor Fields to scenes with the presence of media, adding new challenges and effects from wave propagation theory, which will be reflected in the reconstructions. To counteract them, there is also a posteriori filtering that filters the contribution of the medium of the reconstructions and allows to obtain visualizations of a higher quality. To characterize its behavior in this new configuration of scenes, we had designed a number of experiments allowing us to conclude that the theory of Phasor Fields is sustained by expanding the method to scenes with presence of turbid media. Finally, Phasor Fields is applied in the field of biomedical imaging to see through human skin. This tissue causes all the light that passes through it to lose coherence(i.e. visibility lost). Through experimentation, it is shown how it is possible that despite being a turbid medium, it is possible to see through it.

Bibtex

@article{crespo2019vision,
      author        = "Crespo, Miguel and Jarabo, Adrián",
      title         = "{Visión a través de medios turbios usando Phasor
                       Fields}",
      year          = "2019",
}

Acknowledgements

This project has been carried out at the Graphics and Imaging Lab at the University of Zaragoza. I would like to thank all its members for the good atmosphere and the endless chats of ideas. I cannot imagine a better place than this, in which to have done my Master Thesis. I would especially like to thank my director Adrian for all his help and guidance during the completion of this project. To him and Diego for giving me the opportunity to work on such an exciting project.