单击此处编辑母版标题样式 Class-oriented Regression Embedding 报告人:陈 燚 2011年8月25日 单击此处编辑母版标题样式 报告提纲 1. Background 2. Related Works 2.1 Linear Regression-based Classification 2.2 Neighborhood Preserving Embedding & Sparsity Preserving Projections 3. Class-oriented Regression Embedding 4. Experiments 单击此处编辑母版标题样式 1. Background 单击此处编辑母版标题样式 Background • The minimum reconstruction error criterion is widely used in the recent progress of subspace classification, such as in SRC and LRC J. Wright, A. Yang, S. Sastry, Y. Ma, Robust face recognition via sparse representation, IEEE Trans. Pattern Anal. Mach. Intell. 31 (2), 210–227, 2009. I. Naseem, R. Togneri, and M. Bennamoun. Linear Regression for Face Recognition. IEEE Trans. on PAMI, 2010. 单击此处编辑母版标题样式 A brief review • SRC: y X • LRC y X i i Classification rule: • i is the coefficients of the ith class min y X i i i 单击此处编辑母版标题样式 Nearest Space Classifiers • Definition: The nearest subspace of a given sample • Measurement: Reconstruction Error Stan Z. Li: Face Recognition Based on Nearest Linear Combinations. CVPR 1998: 839-844 单击此处编辑母版标题样式 2.Related Works 单击此处编辑母版标题样式 LRC 线性子空间假设 Xi [x1i , xi2 ,..., xipi ] y Xi βi 最小二乘法 yi Xi X Xi X y T i 1 第i类的重 构结果 T i di y y y i βi X Xi XTi y T i 1 2 样本的类别即是最小重 构误差的类 min di y , i 1, 2,..., c i 单击此处编辑母版标题样式 NPE & SPP Objective Function 2 min xi Wij x j i j s.t. Wij 1 j min aT XMXT a a s.t. aT XXT a 1 M I W T I W The difference between NPE and SPP the reconstructive strategy. NPE: KNN SPP: Global Sparse Xiaofei He, Deng Cai, Shuicheng Yan, and HongJiang Zhang. Neighborhood preserving embedding, ICCV, 1208–1213, 2005. Qiao, L.S., Chen, S.C., Tan, X.Y., Sparsity preserving projections with applications to face recognition. Pattern Recognition 43 (1), 331–341, 2010. 单击此处编辑母版标题样式 3. Class-oriented Regression Embedding 单击此处编辑母版标题样式 Assumption of SRC and LRC • A given sample belongs to the class with minimum reconstruction error Problem: Does this assumption holds well in real world applications? 单击此处编辑母版标题样式 Examples • The training face images 单击此处编辑母版标题样式 Examples 1400 1600 1200 1400 1200 1000 1000 800 800 600 20 600 400 200 0 3 400 200 0 5 10 15 20 25 30 35 40 1200 0 0 5 10 15 20 25 30 35 40 900 800 1000 700 800 17 600 500 600 400 400 14 300 200 200 100 0 0 5 10 15 20 25 30 35 40 0 0 5 10 15 20 25 30 35 40 单击此处编辑母版标题样式 Motivation • LRC uses downsampled images directly for classification, which is not optimal for LRC. • We aim to find the subspace that conforms to the assumption. In this low-dimensional subspace, A sample can be best represented by its intra-class samples. 单击此处编辑母版标题样式 Algorithm • Objective function: min ε y Yi β j i i j j i i j 2 i j • To avoid degenerate solutions, we constraint • Then we have: T X I β βT ββT XT a XXT a Where W1 β 0 a XX a 1 T W2 0 Wc and Wi β1i , βi2 ,..., βini 单击此处编辑母版标题样式 Example • Reconstructive Strategy of CRE NPE and SPP CRE NPE SPP 单击此处编辑母版标题样式 SSS problem X I β βT ββT XT a XXT a XXT is singular in SSS case. We apply PCA to reduce the dimensionality of the origin sample to avoid SSS problem. 单击此处编辑母版标题样式 Ridge Regression-based Classification 线性子空间假设 Xi [x1i , xi2 ,..., xipi ] y Xi βi 最小二乘法 yi Xi X Xi X y T i 1 第i类的重 构结果 T i di y y y i βi X Xi XTi y T i 1 2 样本的类别即是最小重 构误差的类 min di y , i 1, 2,..., c i May be singular • Solution: Ridge Regression min J βi y i Xi βi 2 min J βi y i Xi βi βi 2 βi X Xi X y T i 1 T i 2 βi Xi Xi Il XiT yi T 1 单击此处编辑母版标题样式 Steps • Input: Column sample matrix X [ X1 , X2 ,..., Xc ] • Output: Transform matrix PCRE Step 1: Project the training samples onto a PCA T subspace: X PPCA X Step 2: Construct the global reconstruction coefficient matrix β using X . Step 3: Solve the generalized eigenvectors of X I β βT ββT XT φ XXT φ corresponding to the first d smallest eigenvalues. 单击此处编辑母版标题样式 4. Experiments 单击此处编辑母版标题样式 Experiments on YALE-B Experiments on the YALE-B database Method 5 Train 10 Train 20 Train PCA+NNC 36.1(176) 52.7(362) 68.9(727) LDA+NNC 73.4(37) 87.0(37) 91.3(37) NPE+NNC 65.7(77) 79.0(93) 82.7(152) SPP+NNC 60.2(51) 76.5(72) 84.4(91) CRE+NNC 66.3(43) 58.6(112) 54.3(161) Method 5 Train 10 Train 20 Train PCA+ SRC 72.4(91) 85.8(153) 92.6(192) LDA+ SRC 72.7(37) 84.6(35) 91.7(37) NPE+ SRC 68.8(51) 81.5(80) 90.2(102) SPP+ SRC 69.2(51) 83.4(63) 92.0(82) CRE+ SRC 78.6(65) 89.5(79) 93.4(90) Method 5 Train 10 Train 20 Train PCA+LRC 59.8(101) 82.7(148) 85.6(190) LDA+LRC 65.3(37) 84.1(37) 87.4(37) NPE+LRC 70.4(112) 82.7(205) 85.3(240) SPP+LRC 72.5(51) 86.0(72) 91.3(91) CRE+LRC 80.7(43) 92.4(83) 97.2(161) LRC 58.0 81.7 90.9 1 1 0.9 0.9 0.8 Recognition rates Recognition rates 0.8 0.7 0.6 0.5 0.4 0.7 0.6 0.5 0.3 CRE+LRC CRE+NNC CRE+SRC 0.2 0.1 20 30 40 50 60 70 Dimensions 80 90 100 CRE+LRC CRE+NNC CRE+SRC 0.4 110 30 40 50 60 70 Dimensions 80 90 Comparisons of recognition rates using CRE plus NNC/LRC/SRC on the YALE-B database with 10 and 20 training samples each class respectively. 100 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.5 0.4 CRE+LRC PCA+LRC LDA+LRC NPE+LRC SPP+LRC 0.3 0.2 0.1 20 30 40 50 Dimensions 60 70 Recognition rates Recognition rates 1 0.6 0.5 0.4 CRE+LRC PCA+LRC LDA+LRC SPP+LRC NPE+LRC 0.3 0.2 0.1 30 40 50 60 Dimensions 70 80 Comparisons of recognition rates using 5 methods plus LRC on the YALE-B database with 10 and 20 training samples each class respectively. 90 1 Recognition Rates 0.9 0.8 0.7 0.6 CRE+LRC SPP+SRC LRC 0.5 0.4 30 40 50 60 Dimensions 70 80 90 The recognition rates of CRE plus LRC, SPP plus SRC and direct LRC on the YALE-B databases with 20 training samples of each class. 单击此处编辑母版标题样式 Experiments on FERET Method 3 Train 4 Train 5 Train 6 Train PCA+NNC 29.4(203) 33.0(242) 38.6(253) 42.6(286) LDA+NNC 61.9(33) 65.8(199) 69.9(199) 75.3(199) NPE+NNC 58.6(22) 62.3(51) 66.2(46) 70.1(72) SPP+NNC 36.9(146) 43.2(151) 48.6(176) 50.2(181) CRE+NNC 64.2(53) 69.4(55) 73.0(71) 77.6(82) Method 3 Train 4 Train 5 Train 6 Train PCA+ SRC 53.8(122) 62.8(118) 68.7(121) 73.4(134) LDA+ SRC 66.7(33) 74.6(26) 80.1(36) 86.4(38) NPE+ SRC 64.3(42) 70.7(54) 76.4(60) 82.6(68) SPP+ SRC 52.9(151) 63.7(172) 69.8(185) 74.6(198) CRE+ SRC 75.6(32) 81.4(37) 86.3(43) 91.6(46) Method 3 Train 4 Train 5 Train 6 Train PCA+LRC 40.7(298) 48.6(312) 52.0(335) 54.5(352) LDA+LRC 65.4(39) 73.4(30) 78.6(51) 84.1(62) NPE+LRC 61.3(40) 68.7(65) 72.4(92) 77.4(77) SPP+LRC 50.2(146) 58.7(151) 64.2(176) 68.0(181) CRE+LRC 85.4(53) 90.2(55) 94.1(71) 97.9(82) LRC 42.0 50.6 55.4 61.2 1 1 0.9 0.9 0.8 Recognition rates Recognition rates 0.8 0.7 0.6 0.7 0.6 0.5 0.4 0.5 CRE+LRC CRE+NNC CRE+SRC 0.4 10 20 30 40 Dimensions 50 60 0.3 CRE+LRC CRE+NNC CRE+SRC 0.2 0.1 10 20 30 40 Dimensions 50 Comparisons of recognition rates using CRE plus NNC/LRC/SRC on the FERET database with 5 and 6 training samples each class respectively. 60 1 0.9 0.8 Recognition rates 0.7 0.6 0.5 0.4 CRE+LRC PCA+LRC LDA+LRC SPP+LRC NPE+LRC 0.3 0.2 0.1 0 10 20 30 40 50 Dimensions 60 70 80 A comparison of recognition rates using 5 methods plus LRC on the FERET database with 6 training samples each class respectively. 1 0.9 0.8 Recognition rates 0.7 0.6 0.5 0.4 0.3 0.2 CRE+LRC SPP+SRC LRC 0.1 0 10 20 30 40 50 Dimensions 60 70 80 The recognition rates of CRE plus LRC, SPP plus SRC and direct LRC on the FERET databases with 6 training samples of each class. 单击此处编辑母版标题样式 Experiments on Cenparmi Method PCA LDA NPE SPP CRE NNC 87.6(30) 88.2(9) 85.8(19) 86.9(33) 87.6(33) SRC 90.0(41) 82.6(9) 89.6(21) 92.1(31) 93.6(31) RRC 92.1(32) 84.8(9) 92.4(23) 88.1(33) 95.6(38) Classifier 1 0.9 0.9 0.8 0.8 0.7 0.7 Recognition rates Recognition rates 1 0.6 0.5 0.4 CRE+RRC PCA+RRC LDA+RRC NPE+RRC SPP+RRC 0.3 0.2 0.1 0 5 10 15 20 25 Dimensions 30 35 0.6 0.5 0.4 0.3 CRE+RRC CRE+SRC CRE+NNC 0.2 40 The recognition rate curves of PCA, LDA, NPE, SPP and LSPP plus RRC on the CENPARMI handwritten numeral database. 0.1 0 5 10 15 20 25 Dimensions 30 35 40 The recognition rate curves of CRE plus RRC/SRC/NNC versus the dimensions on the CENPARMI handwritten numeral database. 单击此处编辑母版标题样式 Comparisons 800 1400 700 1200 600 1000 500 800 400 600 300 400 200 200 100 0 0 0 5 10 15 20 25 30 35 40 1600 0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40 900 1400 800 1200 700 1000 600 500 800 400 600 300 400 200 200 100 0 0 5 10 15 20 25 30 35 40 0 单击此处编辑母版标题样式 1200 500 450 1000 400 350 800 300 600 250 200 400 150 100 200 50 0 0 5 10 15 20 25 30 35 40 900 0 0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40 400 800 350 700 300 600 250 500 200 400 150 300 200 100 100 50 0 0 5 10 15 20 25 30 35 40 0 单击此处编辑母版标题样式 谢谢! 报告人:陈 燚 2011年8月25日