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Face Recognition using linear methods (PCA & LDA) and SVM

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Elena Abril

on 23 January 2014

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Transcript of Face Recognition using linear methods (PCA & LDA) and SVM

Baseline Results
Image datasets
400 images of 40 subjects
4 illumination and 6 poses

165 images of 15 individuals
3 different illumination and 8 poses

16128 images of 38 individuals
64 different illumination and 9 poses

Handmade feature extraction
using graphic tablets
Face Recognition using linear methods (PCA, LDA) and SVM
Yale Face database B
PCA and LDA are methods for dimensionality reduction that provide good results with a low computational cost.

SVMs define separation hyperplanes between classes trying to obtain the minimum classification error possible.

Applying these methods to Face Recognition, a good system can be built, with not too high computational requirements.
Elena Abril Medina
Miguel Ángel Fernández Torres

Applications of Signal Processing - 15th January 2014
Face recognition system to cut up crimes and car accidents
System Proposed
PCA (Principal Component Analysis)
LDA (Linear Discriminant Analysis)
SVMs (Support Vector Machines)
Cross validation for selecting optimal parameters.
Linear and RBF kernel functions.
Unsupervised method. Maximize the variance.
Eigenvectors - Eigenfaces
PhD tool (Vitomir Struc)
Supervised method. Data labels in the training set known.
Maximizes distance between classes and minimize the intraclass distance.
PhD tool (Vitomir Struc)

Yale Face database
Model 1: 30% train, 70% test - Model 2: 50% train, 50% test
Model 1: 30% train, 70% test - Model 2: 50% train, 50% test
Model 1: 30% train, 70% test - Model 2: 50% train, 50% test
Yale B
Good performance.
High computational cost.
RBF kernel works better than linear one.
Use a large train set may overfit the model.
Similar or worse performance than baseline.
Lower computational cost.
RBF kernel works better than linear one.
Best performance of the three methods.
Lower computational cost.
Linear kernel works better than RBF one.
Unlock devices.
Security check for payments, online forms...
Safety and health applications
Smart home
Facial feature detection.
Body recognition.
Future work
PhD Tool (2012, Vitomir Struc)

Chih-Chung Chang and Chih-Jen Lin, LIBSVM : a library for support vector machines. ACM Transactions on Intelligent Systems and Technology, 2:27:1--27:27, 2011. Software available at http://www.csie.ntu.edu.tw/~cjlin/libsvm.

2000 Mexican Elections: http://www.thefreelibrary.com/Mexican+Government+Adopts+FaceIt+Face+Recognition+Technology+to...-a062019954

2014 NYPD: http://www.elconfidencial.com/tecnologia/2014-01-03/la-policia-de-nueva-york-ensaya-con-un-coche-patrulla-capaz-de-reconocer-caras_71983/

Davis, M.; T. Ellis (August 1964). "The RAND Tablet: A Man-Machine Graphical Communication Device". ARPA. Retrieved 24 March 2011.

Datasets: http://www.cad.zju.edu.cn/home/dengcai/Data/FaceData.html
What happens if a new
face is passed to the SVM?
LibSVM may produce 3 outputs:
Predicted label
Probability estimates (-b 1)
Each row contains k values indicating the probability of that sample corresponds to each class.
How does it works?
Full transcript