Abstract: An apparatus for calibrating output from an image classifier. The apparatus has an image classifier trained to compute, from an image, confidence values for each of a plurality of skin conditions potentially depicted in the image. The apparatus has a processor to compute a probability score for at least one skin condition by adjusting an associated confidence value using information from an incidence corrected data set which is a plurality of images resampled according to data about an incidence of the skin condition in a population from which the image was captured.