I'd like to know some references for a beginner who has basic background in Riemann surfaces and differential geometry, and would like to start learning/working on more applied areas, medical imaging/imaging problems in particular. I searched it online, but it was not so productive for me.

I was also wondering whether one must learn the theory of discrete differential geometry/discrete Riemann surfaces in order to work in these areas; I've sometimes seen faculty webpages mentioning their research in both areas.

Thanks in advance!