Optimal Features ASM

Texture description based on Taylor series

Grids centered at the landmarks for local analysis

Non linear classifier (kNN) for inside-outside labeling

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B. van Ginneken, A.F. Frangi, J.J. Staal, B.M. ter Haar Romeny, and M.A. Viergever (2002)IEEE Transactions on Medical Imaging, 21(8):924–933

Optimal Features ASM Face is too complex for the proposed

labeling Thin zones generate profile variations Classes unbalance in high curvature

points kNN slow (set dependent) Image features dependent on rotation

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Invariant Optimal Features ASM1 2

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F.M. Sukno, S. Ordas, C. Butakoff, S. Cruz, and A.F. FrangiIEEE Transactions on Pattern Analysis and Machine Intelligence, 29(7):1105–1117

Invariant Optimal Features ASM Distance-based labeling

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2R = 1 L = 18

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180 profiles of man and women with IOF-ASM

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Invariant Optimal Features ASM1 2

Multi-valued neuron classifier Single neuron Very fast

Appropriate combination of derivatives allows for invariance to rigid transformations

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Segmentation tests1 2

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Experiments on 3400+

images

Point to curve errorPoint to point error

IOFASM vs ASMDataset

Images

Error

AR 532 - 33.2 %

Equinox

546 - 25.2 %

XM2VTS

2360 - 33.8 %

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IOFASM vs ASM

ASM IOF-ASM

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Identity Verification: TextureBased on texture

Eigenfaces-like approach from the segmentation results

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Identity Verification: Texture1 2

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Related work1 2

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Conclusions on IOF-ASM1 2

By using more elaborate descriptions of the texture it is possible to increase the accuracy of ASMs IOF-ASM provides a generic framework Features are optimized for every landmark

Allows for a trade off between accuracy and speed Feature selection: –15% error / –50% time

About 30% more accurate than ASM in facial feature localization Derives in better identification rates

Invariant to in-plane rotations 12

Out-of-plane Rotations Environment

constraints● Surveillance

systems● Car driver images

ASM:● Similarity does not

remove 3D pose ● Multiple-view

database Other approaches

● Non-linear models● 3D models: multiple

views

AV@CAR Database

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