1. A method of processing an input image, comprising: determining values of features in a discriminant space for respective pixels of the input image; and classifying the pixels into a nonhuman animal integument class based on the respective feature values and a mapping that segments the discriminant space into one or more regions of feature values representing pixels associated with a nonhuman animal integument characteristic and one or more regions of feature values representing pixels unassociated with the nonhuman animal integument characteristic.