The equivalence of 2DLPP to LPP and (2D)2LPP for face recognition
Jun Yang, Yanli Liu · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2011
2DLPP is a valid dimensions reduction method which directly extracts feature from image matrix and can detect the intrinsic manifold structure of data by preserving the local information of training data. We analyze the relation between 2DLPP and LPP. We demonstrate they are equivalent on some special conditions. Conventional 2DLPP is working in the row direction of images. We proposed an alternative 2DLPP which is working in the column direction of images. By simultaneously considering the row and column directions, we develop the two-directional 2DLPP, i.e. (2D)2LPP. The proposed method not only extracts feature with lower dimension than 2DLPP, but also take full advantage of row and column structure information of images. Experiment results on two standard face databases demonstrate the effectiveness of the proposed method.