Imaging through strongly diffuse media can be extremely challenging yet has many applications ranging from seeing though thick fog to imaging inside the human body. A number of approaches have been demonstrated for imaging over a relatively small number of transport mean free paths, TMFPs, defined as the distance over which scattering leads to complete loss information of the original photon propagation direction. However, imaging deep inside the body, for example all the way through the head, requires transmission through more than 100 TMFPs. Whereas late photons degrade image retrieval with weak diffusion, we show how in the presence of deep diffusion including the late photons in the inverse retrieval enhances the image reconstruction. An analysis using information theory sheds light on how information moves from the early photons towards later arrival times and provides insight into how to improve inverse image retrieval.
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