17. The face recognition method of claim 11 , wherein each of the registration models previously stored in the user registration model DB comprises a plurality of sub-models, facial feature vectors of which have similarities therebetween that are greater than or equal to a threshold.
18. The face recognition method of claim 17 , wherein, in the adding and updating the selected facial feature vector, the selected facial feature vector is added to a record of a specific sub-model when similarity between the selected facial feature vector and the facial feature vector of the sub-model is equal to or greater than the threshold, and a new sub-model is created and the selected facial feature vector is added to a record of the new sub-model when the similarity is less than the threshold.