Video Manifolds Selen Atasoy MICCAI 2011 Tutorial Image Spaces - - PowerPoint PPT Presentation
Video Manifolds Selen Atasoy MICCAI 2011 Tutorial Image Spaces - - PowerPoint PPT Presentation
Image Similarities for Learning Video Manifolds Selen Atasoy MICCAI 2011 Tutorial Image Spaces Image Manifolds Tenenbaum2000 Roweis2000 Tenenbaum2000 [ Tenenbaum2000: J. B. Tenenbaum, V. Silva, J. C. Langford : A global geometric framework for
Image Spaces
Roweis2000 Tenenbaum2000 Tenenbaum2000
Image Manifolds
[Tenenbaum2000: J. B. Tenenbaum, V. Silva, J. C. Langford: A global geometric framework for nonlinear dimensionality reduction. Science, 290(5500), 2000.] [Roweis2000: S. T. Roweis, L. K. Saul: Nonlinear dimensionality reduction by locally linear
- embedding. Science, 290(5500), 2000]
Atasoy2010 Pless2003
Video Manifolds
[Pless2003: R. Pless: Using Isomap to Explore Video Sequences: ICCV, 2003.] [Atasoy2010: S. Atasoy, D. Mateus, J. Lallemand, A. Meining, G.Z. Yang, N. Navab: Endoscopic Video Manifolds, MICCAI, 2010.] [Atasoy2011: S. Atasoy, D. Mateus, A. Meining, G.Z. Yang, N. Navab: Targeted Optical Biopsies for Surveillance Endoscopies, MICCAI, 2011.]
Theoretical Background
Manifold Learning
- High dimensional data points
lying on or near a manifold
- Low dimensional representation
- Find a mapping
that best preserves ... ???
Manifold Learning
- 1. Define a matrix based on the
relations between data points
- 2. Compute the eigenvectors &
eigenvalues
- 3. Embed each sample
A General Recipe
Manifold Learning A General Recipe
Method Operator/Matrix Preserved Objective Function PCA Covariance matrix Variance of the dataset / Euclidean distances between data points Laplacian Eigenmaps Graph Laplacian Distances within the local neighbourhood
- f each data point
ISOMAP Geodesic distance matrix Geodesic distances between data points LLE Reconstruction weights Reconstruction weights within the local neighbourhood
- f each data point
Manifold Learning
- Rayleigh-Ritz Theorem:
- Recall:
– Scalar product: – Scalar product in H: – Norm: – Norm in H:
Why does it work?
eigenvalues eigenvectors
Discrete Domain
- vectors
- Continuous Domain
- functions
- Manifold Learning
Why does it work?
Schwarz’s Kernel Theorem: Each linear operator is given as an integration against a unique kernel. That kernel is the impulse response of the linear system to an impulse (a delta function).
Discrete Domain
- vectors
- Continuous Domain
- functions
- Manifold Learning
Why does it work?
Discrete Domain
- vectors
- Continuous Domain
- functions
- Manifold Learning
Why does it work?
The matrix H defines:
- which operator is applied
- which (Hilbert) space we are working in
- which quantity will be conserved
Laplacian Eigenmaps
Manifold Learning
- Solve
- Find the eigenvectors of the graph Laplacian
- Equivalent to solving the Helmholtz Equation
Laplacian Eigenmaps
[Belkin2003: M. Belkin, P. Niyogi: Laplacian eigenmaps for dimensionality reduction and data
- representation. Neural computation, 15(6), 1373-1396. MIT Press, 2003]
[Levy2010] [Levy2010]
Manifold Learning Laplacian Eigenmaps - Interpretation
[Chladni1787: E. Chladni: Discoveries in the Theory of Sound, 1787.] [Levy2010: B. Levy: Spectral Geometry Processing: ACM SIGGRAPH Course Notes, 2010.]
[Chladni1787]
Non-linear Manifold Learning Laplacian Eigenmaps - Interpretation
- Manifold learning as bending, stretching without cutting or creating wholes
- Vibrational modes are preserved while bending the manifold
Endoscopic Video Manifolds (EVMs)
Endoscopic Video Manifolds
- Clustering Uninformative Frames
Challenges
Endoscopic Video Manifolds Clustering Uninformative Frames
Endoscopic Video Manifolds Clustering Uninformative Frames
Informative frame & power spectrum Uninformative frame & power spectrum
[Atasoy2010: S. Atasoy, D. Mateus, J. Lallemand, A. Meining, G.Z. Yang, N. Navab: Endoscopic Video Manifolds, MICCAI, 2010.]
Uninformative frame Informative frame
Endoscopic Video Manifolds Clustering Uninformative Frames
[Atasoy2010: S. Atasoy, D. Mateus, J. Lallemand, A. Meining, G.Z. Yang, N. Navab: Endoscopic Video Manifolds, MICCAI, 2010.]
Endoscopic Video Manifolds
- Significant change in
endoscope viewpoint
- Small overlap between
frames showing the same scene
- Scenes do not necessarily
contain distinctive features
Challenges
Endoscopic Video Manifolds
Cluster 1
338 frames
Cluster 2
150 frames
Cluster 3
137 frames
Cluster 4
102 frames
Cluster 5
98 frames
Cluster 6
78 frames
Cluster 7
71 frames
Cluster 8
71 frames
Cluster 9
44 frames
Cluster 10
38 frames
- 0.06
- 0.04
- 0.02
0.02 0.04 0.06 0.08
- 0.1
- 0.05
0.05 0.1
- 0.12
- 0.1
- 0.08
- 0.06
- 0.04
- 0.02
0.02 0.04
Cluster 1 Cluster 2 Cluster 3 Cluster 4 Cluster 5 Cluster 6 Cluster 7 Cluster 8 Cluster 9 Cluster 10
Clustering Endoscopic Scenes – Euclidean Distance
[Belkin2003: M. Belkin, P. Niyogi: Laplacian eigenmaps for dimensionality reduction and data representation. Neural computation, 15(6), 1373-1396. MIT Press, 2003] [Atasoy2010: S. Atasoy, D. Mateus, J. Lallemand, A. Meining, G.Z. Yang, N. Navab: Endoscopic Video Manifolds, MICCAI, 2010.]
Endoscopic Video Manifolds Clustering Endoscopic Scenes – Euclidean Distances
- 0.06
- 0.04
- 0.02
0.02 0.04 0.06 0.08
- 0.1
- 0.05
0.05 0.1
- 0.12
- 0.1
- 0.08
- 0.06
- 0.04
- 0.02
0.02 0.04
Cluster 1 Cluster 2 Cluster 3 Cluster 4 Cluster 5 Cluster 6 Cluster 7 Cluster 8 Cluster 9 Cluster 10
Cluster 3
Endoscopic Video Manifolds Clustering Endoscopic Scenes - NCC
Cluster 1
389 frames
Cluster 2
137 frames
Cluster 3
103 frames
Cluster 4
98 frames
Cluster 5
85 frames
Cluster 6
82 frames
Cluster 7
81 frames
Cluster 8
64 frames
Cluster 9
44 frames
Cluster 10
44 frames
- 0.08
- 0.06
- 0.04
- 0.02
0.02 0.04
- 0.1
- 0.05
0.05 0.1
- 0.12
- 0.1
- 0.08
- 0.06
- 0.04
- 0.02
0.02 0.04
Cluster 1 Cluster 2 Cluster 3 Cluster 4 Cluster 5 Cluster 6 Cluster 7 Cluster 8 Cluster 9 Cluster 10
[Atasoy2010: S. Atasoy, D. Mateus, J. Lallemand, A. Meining, G.Z. Yang, N. Navab: Endoscopic Video Manifolds, MICCAI, 2010.]
Endoscopic Video Manifolds Clustering Endoscopic Scenes - NCC
Euclidean Distance Normalized Cross Correlation
[Atasoy2010: S. Atasoy, D. Mateus, J. Lallemand, A. Meining, G.Z. Yang, N. Navab: Endoscopic Video Manifolds, MICCAI, 2010.]
Endoscopic Video Manifolds Clustering Endoscopic Scenes - NCC
Endoscopic Video Manifolds
- Change the adjacency matrix to include temporal
constraints
Clustering Endoscopic Scenes with Temporal Constraints
[Atasoy2011: S. Atasoy, D. Mateus, A. Meining, G.Z. Yang, N. Navab: Targeted Optical Biopsies for Surveillance Endoscopies, MICCAI, 2011]
Endoscopic Video Manifolds
Clustering Endoscopic Scenes with Temporal Constraints
- 0.04
- 0.02
0.02 0.04 0.06 0.08 0.1
- 0.05
0.05 0.1 0.15
- 0.1
- 0.08
- 0.06
- 0.04
- 0.02
0.02 0.04
Cluster 1 Cluster 2 Cluster 3 Cluster 4 Cluster 5 Cluster 6 Cluster 7 Cluster 8 Cluster 9 Cluster 10
Cluster 1
344 frames
Cluster 2
143 frames
Cluster 3
126 frames
Cluster 4
120 frames
Cluster 5
112 frames
Cluster 6
88 frames
Cluster 7
55 frames
Cluster 8
53 frames
Cluster 9
43 frames
Cluster 10
43 frames
[Atasoy2011: S. Atasoy, D. Mateus, A. Meining, G.Z. Yang, N. Navab: Targeted Optical Biopsies for Surveillance Endoscopies, MICCAI, 2011]
Acknowledgements
- Prof. Nassir
Navab
- Prof. Guang-Zhong
Yang
- Prof. Alexander
Meining
- Dr. Diana
Mateus