Object Detection and Segmentation from Joint Embedding of Parts and - - PowerPoint PPT Presentation

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Object Detection and Segmentation from Joint Embedding of Parts and - - PowerPoint PPT Presentation

Object Detection and Segmentation from Joint Embedding of Parts and Pixels Michael Maire 1 , Stella X. Yu 2 , Pietro Perona 1 1 California Institute of Technology - Pasadena, CA 91125 2 Boston College - Chestnut Hill, MA 02467 Segmentation


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Object Detection and Segmentation from Joint Embedding of Parts and Pixels

Michael Maire1, Stella X. Yu2, Pietro Perona1

1California Institute of Technology - Pasadena, CA 91125 2Boston College - Chestnut Hill, MA 02467

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Segmentation Detection

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Segmentation Detection

  • Perceptual Grouping Framework
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Ingredients

Plug in state-of-the-art components:

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Ingredients

Plug in state-of-the-art components: low-level cues: color, texture, edges

[Arbel´ aez, Maire, Fowlkes, Malik, PAMI 2011]

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Ingredients

Plug in state-of-the-art components: low-level cues: color, texture, edges

[Arbel´ aez, Maire, Fowlkes, Malik, PAMI 2011]

top-down parts: poselets for person detection

[Bourdev, Maji, Brox, Malik, ECCV 2010]

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Ingredients

Plug in state-of-the-art components: low-level cues: color, texture, edges

[Arbel´ aez, Maire, Fowlkes, Malik, PAMI 2011]

top-down parts: poselets for person detection

[Bourdev, Maji, Brox, Malik, ECCV 2010]

PASCAL VOC 2010 Person Category: Improved Detection and Segmentation

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Grouping Relationships

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Grouping Relationships

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Pixel Affinity: Color, Texture Similarity

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Pixel Affinity: Color, Texture Similarity

b

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Pixel Affinity: Color, Texture Similarity

b

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Part Affinity: Geometric Compatibility

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Part Affinity: Geometric Compatibility

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pixels

b b

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pixels

b b

parts

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pixels

b b

parts surround

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pixels

b b

parts surround

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pixels

b b

parts surround

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pixels

b b

parts surround figure/ground prior

b C

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pixels

b b

parts surround figure/ground prior

bC

Angular Embedding

⇒ ⇒ ⇒

  • bjects

figure/ground segmentation

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Angular Embedding

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Angular Embedding p q

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Angular Embedding p q

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Angular Embedding p q

Given:

◮ Relative ordering Θ(·, ·) ◮ Confidence on relationships C(·, ·)

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Angular Embedding p q

Given:

◮ Relative ordering Θ(·, ·) ◮ Confidence on relationships C(·, ·)

Compute:

◮ Global ordering θ(·) ◮ Embed into unit circle:

p → z(p) = eiθ(p)

θ

  • p
  • q
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Angular Embedding p q

Given:

◮ Relative ordering Θ(·, ·) ◮ Confidence on relationships C(·, ·)

Compute:

◮ Global ordering θ(·) ◮ Embed into unit circle:

p → z(p) = eiθ(p)

θ

  • p
  • q

Subject to:

◮ Linear constraints on embedding solution in columns of U

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i 1 −1

z(p) z(q) z(r) minimize: ε =

p

  • q C(p,q)
  • p,q C(p,q) · |z(p) − ˜

z(p)|2

[Yu, PAMI 2011]

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i 1 −1

z(p) z(q) z(r) z(r)eiΘ(p,r) z(q)eiΘ(p,q) C(p, r) C ( p , q ) Θ(p, r) Θ(p, q) minimize: ε =

p

  • q C(p,q)
  • p,q C(p,q) · |z(p) − ˜

z(p)|2

[Yu, PAMI 2011]

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i 1 −1

z(p) z(q) z(r) z(r)eiΘ(p,r) z(q)eiΘ(p,q) C(p, r) C ( p , q ) Θ(p, r) Θ(p, q)

˜ z(p)

minimize: ε =

p

  • q C(p,q)
  • p,q C(p,q) · |z(p) − ˜

z(p)|2

[Yu, PAMI 2011]

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b b

b C

Cp Cq (Cs, Θs) (Cf , Θf ) U

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pixels

  • parts

surround prior

  • C =

    Cp α · Cq β · Cs γ · Cf β · C T

s

γ · C T

f

    Θ = Σ−1     Θs Θf −ΘT

s

−ΘT

f

   

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Angular Embedding

Relax to generalized eigenproblem QPQz = λz: P = D−1W Q = I − D−1U(UTD−1U)−1UT with D and W defined as: D = Diag(C1n) W = C • eiΘ Eigenvectors {z0, z1, ..., zm−1} embed pixels and parts into Cm

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Angular Embedding

∠z0 encodes global ordering z1, z2, ..., zm−1 encode grouping

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Angular Embedding

∠z0 encodes global ordering z1, z2, ..., zm−1 encode grouping if Θ = 0 ⇒ Normalized Cuts (grouping without ordering)

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Decoding Eigenvectors: Object Detection

ℜ(z0) ℜ(z1) ℜ(z2) ℑ(z0) ℑ(z1) ℑ(z2) Ordering Grouping

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Decoding Eigenvectors: Object Detection

ℜ(z0) ℜ(z1) ℜ(z2) ℑ(z0) ℑ(z1) ℑ(z2)

b b b

Ordering Grouping

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Decoding Eigenvectors: Object Detection

ℜ(z0) ℜ(z1) ℜ(z2) ℑ(z0) ℑ(z1) ℑ(z2)

b b b b b b

Ordering Grouping

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Decoding Eigenvectors: Object Detection

ℜ(z0) ℜ(z1) ℜ(z2) ℑ(z0) ℑ(z1) ℑ(z2)

b b b b b b b b b

Ordering Grouping

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Decoding Eigenvectors: Object Detection

ℜ(z0) ℜ(z1) ℜ(z2) ℑ(z0) ℑ(z1) ℑ(z2)

b b b b b b b b b

Ordering Grouping

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Decoding Eigenvectors: Object Detection

ℜ(z0) ℜ(z1) ℜ(z2) ℑ(z0) ℑ(z1) ℑ(z2)

b b b b b b b b b

Ordering Grouping

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Decoding Eigenvectors: Object Detection

ℜ(z0) ℜ(z1) ℜ(z2) ℑ(z0) ℑ(z1) ℑ(z2)

b b b b b b b b b

Ordering Grouping

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Decoding Eigenvectors: Object Detection

ℜ(z0) ℜ(z1) ℜ(z2) ℑ(z0) ℑ(z1) ℑ(z2)

b b b b b b b b b

Ordering Grouping

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Decoding Eigenvectors: Figure/Ground

ℜ(z) ℑ(z) z0 z1 z2 z3 z4

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Decoding Eigenvectors: Figure/Ground

ℜ(z) ℑ(z) z0 z1 z2 z3 z4 ⇐ ℑℜ(z) ∠z0 ∇z1 ∇z2 ∇z3 ∇z4

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Decoding Eigenvectors: Segmentation

ℑℜ(z) ∠z0 ∇z1 ∇z2 ∇z3 ∇z4 Figure/Ground

  • Hierarchical Segmentation

[Arbel´ aez, Maire, Fowlkes, Malik, PAMI 2011]

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Decoding Eigenvectors: Object Segmentation

Assign pixels pk to objects Qi via parts qj: pk → argmin

Qi

  • min

qj∈Qi{Dist(pk, qj)}

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Decoding Eigenvectors: Object Segmentation

Assign pixels pk to objects Qi via parts qj: pk → argmin

Qi

  • min

qj∈Qi{Dist(pk, qj)}

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Decoding Eigenvectors

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Results: PASCAL 2010 Person Category

Detections Poselet Mask F/G Mask Segmentation

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Results: PASCAL 2010 Person Category

Detections Poselet Mask F/G Mask Segmentation

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Results: PASCAL 2010 Person Category

◮ Segmentation task score: 41.1 (35.5 for poselet baseline)

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Results: PASCAL 2010 Person Category

◮ Segmentation task score: 41.1 (35.5 for poselet baseline) ◮ 11% relative improvement due to better detection

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Summary

◮ Simultaneous segmentation and detection:

◮ Part detectors → figure pop-out, object grouping ◮ Color, texture → pixel grouping

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Summary

◮ Simultaneous segmentation and detection:

◮ Part detectors → figure pop-out, object grouping ◮ Color, texture → pixel grouping

◮ Graph:

◮ Parts and pixels as nodes ◮ Links encode multiple relationship types

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Summary

◮ Simultaneous segmentation and detection:

◮ Part detectors → figure pop-out, object grouping ◮ Color, texture → pixel grouping

◮ Graph:

◮ Parts and pixels as nodes ◮ Links encode multiple relationship types

◮ Embedding: graph nodes → Cm

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Summary

◮ Simultaneous segmentation and detection:

◮ Part detectors → figure pop-out, object grouping ◮ Color, texture → pixel grouping

◮ Graph:

◮ Parts and pixels as nodes ◮ Links encode multiple relationship types

◮ Embedding: graph nodes → Cm ◮ Decode:

◮ Figure/ground ◮ Image segmentation ◮ Detected objects ◮ Segmentation of each object instance

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Summary

◮ Simultaneous segmentation and detection:

◮ Part detectors → figure pop-out, object grouping ◮ Color, texture → pixel grouping

◮ Graph:

◮ Parts and pixels as nodes ◮ Links encode multiple relationship types

◮ Embedding: graph nodes → Cm ◮ Decode:

◮ Figure/ground ◮ Image segmentation ◮ Detected objects ◮ Segmentation of each object instance

◮ Better person detection and segmentation on PASCAL

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Thank You