Focusing on the high loss of subtle facial details in traditional algorithm
a face image super-resolution algorithm through global reconstruction and position-patch based residue compensation is presented. The optimal coefficients of the low-resolution training images are computed and transformed into high-resolution space to reconstruct the global high-resolution image. The residue training set is obtained by a smoothing and down-sampled processing. The residue compensation based on position is performed to better recover face subtle details using the residue training set. Experimental results show that the proposed approach synthesizes high-resolution faces with more details and the average of peak signal-to-noise ratios is improved about 0.65 dB to 3.55 dB compared with some existing learning-based methods.
SONG Rui, JIA Yuan, WU Chengke, et al. A maximum posteriori super-resolution algorithm for adaptive estimation of blur parameter [J]. Journal of Xi'an Jiaotong University, 2008, 42(10):1254-1258.
WANG Xiaogang, TANG Xiaoou. Hallucinating face by eigentransformation [J]. IEEE Transactions on Systems Man and Cybernetics:Part C, 2005, 35(3): 425-434.
PARK J S, LEE S W. An example-based face hallucination method for single-frame, low-resolution facial images [J]. IEEE Transactions on Image Processing, 2008, 17(10): 1806-1816.
ROWEIS S T, SAUL L K. Nonlinear dimensionality reduction by locally linear embedding [J]. Science, 2000, 22(12): 2323-2326.
SAUL L K. An Introduction to Locally Linear Embedding [EB/OL].(2001-01-01)[2008-04-05]. http:∥www.cs.toronto.edu/~roweis/lle/publications.html.
LIU Ce, SHUM H Y, ZHANG C S. A two-step approach to hallucinating faces: global parametric model and local nonparametric model [C]∥Proceeding of the Inter Conference on Image and Graphics.Piscataway, NJ, USA: IEEE, 2001: 192-198.
GAO Wen, CAO Bo, SHAN Shiquan, et al. The CAS-PEAL large-scale Chinese face database and baseline evaluations [J]. IEEE Transactions on System Man, and Cybernetics: Part A, 2008, 38(1): 149-161.