1. A method comprising: identifying a set of training vectors, wherein each training vector is mapped to either a male gender or a female gender, and wherein each training vector represents facial landmarks derived from a respective facial image; identifying an input vector of facial landmarks, wherein the facial landmarks of the input vector are derived from a particular facial image; selecting, from the input vector, a feature vector containing a subset of the facial landmarks; performing, by a computing device, a weighted comparison between the feature vector and each of the training vectors; and based on a result of the weighted comparison, classifying the particular facial image as either the male gender or the female gender.