1. A system for detecting a face, comprising: a memory unit for storing eigenvectors and weights extracted from a plurality of training images; a facial image recognition unit for extracting eigenvectors and weights of respective face components from an input facial image; and a facial image decision unit for deriving an algorithm for deciding whether the facial image is occluded, using the eigenvectors and weights of the training images stored in the memory unit, and for deciding whether the input facial image is occluded, by assigning the eigenvectors and weights of the input image extracted in the facial image recognition unit into the derived algorithm.