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Outline Multilinear Analysis

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Presentation on theme: "Outline Multilinear Analysis"— Presentation transcript:

1 Outline Multilinear Analysis
M. A. O. Vasilescu and D. Terzopoulos, “Multilinear Independent Components Analysis,” CVPR 2005

2 Motivations Natural images are generated by the interaction of multiple factors related to scene structure, illumination, and imaging November 10, 2018 Computer Vision

3 Motivations November 10, 2018 Computer Vision

4 Separating Styles from Content
November 10, 2018 Computer Vision

5 Separating Styles from Content
November 10, 2018 Computer Vision

6 Separating Styles from Content
November 10, 2018 Computer Vision

7 Bilinear Model Suppose that we want to represent both style s and content c with vectors of parameters Let ysc denote a K-dimensional observation vector in style s and content class c November 10, 2018 Computer Vision

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11 How to Learn the Bases and Coefficients
Learning is done by minimizing total squared error over the entire training set Again the solution is given by a SVD decomposition November 10, 2018 Computer Vision

12 How to Learn the Bases and Coefficients
For symmetric models, we also minimize the total squared error over the training set This is minimized using an iterative procedure November 10, 2018 Computer Vision

13 Classification Example
November 10, 2018 Computer Vision

14 Classification Example
When the model is trained on 10 faces and tested on the remaining one 1-NN achieves an accuracy of 53.9%±4.3% The proposed method achieves 73.9%±6.7% when parameters are determined automatically It achieves 80.6%±7.5% when optimal parameter values are used November 10, 2018 Computer Vision

15 Extrapolation November 10, 2018 Computer Vision

16 Extrapolation November 10, 2018 Computer Vision

17 Translation November 10, 2018 Computer Vision

18 Multilinear Analysis Tensors are multilinear mappings over a set of vector spaces An order N tensor is given by Mode-n vectors are given by They result in a mode-n flattening November 10, 2018 Computer Vision

19 Multilinear Analysis November 10, 2018 Computer Vision

20 Multilinear Analysis November 10, 2018 Computer Vision

21 Multilinear Analysis Mode-n product of a tensor and matrix is given by
A tensor of n factors November 10, 2018 Computer Vision

22 Mode-n SVD November 10, 2018 Computer Vision

23 TensorFaces Weizmann face image database 28 male subjects
photographed in 5 viewpoints, 4 illuminations, and 3 expressions Images are aligned to a reference face using a global rigid optical flow and then downsized by a factor of 3 and cropped, yielding a total of 7943 pixels per image within the elliptical cropping window November 10, 2018 Computer Vision

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25 Weizmann Face Dataset November 10, 2018 Computer Vision

26 TensorFaces The dataset is then represented by a tensor of order 5
November 10, 2018 Computer Vision

27 TensorFaces November 10, 2018 Computer Vision

28 TensorFaces November 10, 2018 Computer Vision

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32 TensorFaces November 10, 2018 Computer Vision

33 TensorFaces The bases for TensorFaces are given by November 10, 2018
Computer Vision

34 Face Recognition First experiment
TensorFaces are trained on an ensemble comprising images of 23 people, captured from 3 viewpoints (0,±34 degrees), with 4 illumination conditions (center, left, right, left + right) It is tested on other images in this 23 person dataset acquired from 2 different viewpoints (±17 degrees) under the same 4 illumination conditions In this test scenario, the PCA method recognized the person correctly 61% of the time while TensorFaces recognized the person correctly 80% of the time. November 10, 2018 Computer Vision

35 Face Recognition The second experiment
In a second experiment, TensorFaces is trained on images of 23 people 5 viewpoints (0,±17,±34 degrees), 3 illuminations (center light, left light, right light) Tested on the 4th illumination (left + right) PCA yielded a poor recognition rate of 27% while Tensorfaces achieved a recognition rate of 88% November 10, 2018 Computer Vision

36 Dimension Reduction November 10, 2018 Computer Vision

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38 N-Mode Orthogonal Iteration Algorithm
November 10, 2018 Computer Vision

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41 Multilinear ICA Similar to MPCA, MICA is done using an n-mode ICA algorithm November 10, 2018 Computer Vision

42 Different ICA Architectures
Architecture I ICA computes independent components of DT Architecture II ICA computes independent components of D November 10, 2018 Computer Vision

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44 MICA November 10, 2018 Computer Vision

45 MICA November 10, 2018 Computer Vision

46 MICA November 10, 2018 Computer Vision

47 Recognition Experiment
November 10, 2018 Computer Vision

48 TensorTextures Similar idea can be used for image synthesis
November 10, 2018 Computer Vision

49 TensorTextures November 10, 2018 Computer Vision

50 TensorTextures November 10, 2018 Computer Vision

51 TensorTextures November 10, 2018 Computer Vision

52 TensorTextures November 10, 2018 Computer Vision

53 TensorTextures November 10, 2018 Computer Vision

54 TensorTextures November 10, 2018 Computer Vision

55 Comparison November 10, 2018 Computer Vision


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