Image Bioinformatics Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom. david.shotton@zoo.ox.ac.uk|Image Bioinformatics Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom. david.shotton@zoo.ox.ac.uk|Image Bioinformatics Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom. david.shotton@zoo.ox.ac.uk|Image Bioinformatics Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom. david.shotton@zoo.ox.ac.uk