1. A method comprising: obtaining an input vector of facial landmarks, wherein the facial landmarks of the input vector are derived from a given facial image, and wherein the facial landmarks of the input vector are identified based on their ability to represent anthropometric characteristics of the given facial image; performing, by a computing device, a weighted comparison between the input vector and each of a plurality of training vectors, wherein each training vector is mapped to at least one of a plurality of categories, and wherein each training vector represents facial landmarks derived from a different respective facial image; and based on a result of the weighted comparison, classifying the given facial image into a category of the plurality of categories.