Face Recognition By Sunny Tang
Outline Introduction Requirements Eigenface Fisherface Elastic bunch graph Comparison
Introduction What is face recognition? Applications Security applications Image search engine
Requirements Accurate Efficient Light invariant Rotation invariant
Eigenface Euclidean distance between images Principal component analysis (PCA) For training set T1, T2, …… TM Average face ψ = 1/MΣ TM Difference vector φi = Ti – ψ Covariance matrix C = 1/MΣ φn φTn
PCA
Recognition Projection in Eigenface Projection ωi = W (T – ψ) W = {eigenvectors} Compare projections
Fisherface Similar approach to Eigerface PCA Fisher’s Linear Discriminant (FLD) PCA Scatter Matrix Projection Matrix
Fisherface FLD Between-class scatter matrix Within-class scatter matrix Projection Matrix
FLD
Elastic Bunch Graph Gabor wavelet decomposition Gabor kernels
Gabor Filters
Jets Small patch gray values Wavelet transform
Comparing Jets Amplitude similarity Phase similarity
Comparing Jets
Face Bunch Graphs (FBG) Stack like general representation Two types of FBG: Normalization stage Graph extraction stage Graph similarity function
Graph Extraction Step 1: find approximate face position Step 2: refine position and size Step 3: refine size and find aspect ratio Step 4: local distortion
Recognition Comparing image graph Recognized for highest similarity
Comparison Eigenface Fisherface Elastic bunch graph Fast, easy implementation Fisherface Light invariant, better classification Elastic bunch graph Rotation, light, scale invariant
Q & A Section