Comparative study of dimension reduction and recognition algorithms of DCT and 2DPCA

Based on the application of DCT (discrete cosine transform) in the image compression, the feasibility of DCT to be used in image feature dimension reduction is analyzed, and the basic principle of the image feature dimension reduction based on DCT is given in this paper. And then, taking the face recognition and the facial expression recognition as the research background, the theoretical analysis that DCT algorithm has the higher recognition than 2DPCA (two-dimensional principal component analysis) in the face recognition and the facial expression recognition is given under the condition that DCT and 2DPCA algorithms have the approximate dimension reduction effect. At last, the comparative simulation experiment is performed on DCT and 2DPCA algorithms respectively by use of the AT&T face database and JAFFE facial expression database.