Discriminating dysplasia: Optical tomographic texture analysis of colorectal polyps

•The first study of automatic image analysis of colorectal polyps using OPT images.•A rigorous evaluation of three state-of-the-art 3-D texture feature representations.•A classification model and an ordinal regression model are compared and contrasted.•Issues of class imbalance and output calibration are explored empirically.•Two strategies for fast approximation of non-linear kernels are evaluated.