Symmetry detection

This will probably become one of our modalities in the future: symmetry !

Thanks to the guys at hs-niederrhein, there is symmetry-detection-code that can already be used
for some first estimates:

This software implements the gradient product transform for symmetry
detection that is described in the paper

C. Dalitz, R. Pohle-Froehlich, F. Schmitt, M. Jeltsch:
“The gradient product transform for symmetry detection
and blood vesselm extraction.” International Conference on
Computer Vision Theory and Applications (VISAPP), pp. 177-184,
2015

And the first results look quite promising: