Structure Preserving Object Tracking

Lu Zhang and Laurens van der Maaten

Pattern Recognition & Bioinformatics Group

Delft University of Technology, The Netherlands

Model-Free Tracking

To track object based on a single annotation

A Simple Model-Free Tracker

w

HOG + linear SVM

Initialize tracker

A Simple Model-Free Tracker

w

Update appearance model online

Problems

Problems

• Similar appearance

• Occlusion

• Fast motion

• Camera shaking

•…

Why are they problems?

Do We Have More Information ?

Do We Have More Information ?

Spatial Relationship !

Does It Help in Tracking ?

SPOT Tracker

Model

Model Structure constraint, e.g. MST

Model

Score

Appearance Score

Score Structure Deformation

Appearance Score

Learning: Structured SVM

𝐶 𝐶 𝐶 𝐶

is small is large

Tsochantaridis, et al 2005

Experiment I: Multiple-Object Tracking

0

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80

100

120

140

160

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200

Err

or

(pix

el)

no-SPOT

mst-SPOT

Experiment I: Multiple-Object Tracking

Experiment I: Multiple-Object Tracking

0

20

40

60

80

100

120

140

160

180

Err

or

(pix

el)

OAB (Grabner et al 2006)

TLD (Kalal et al 2010)

mst-SPOT

Experiment II: Single-Object Tracking

Select salient parts to be the vertices

Experiment II: Single-Object Tracking

Experiment II: Single-Object Tracking

0

5

10

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20

25

30

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40

45

Err

or

(pix

el)

no-SPOT

mst-SPOT

Conclusion

Spatial constraints do help tracking !

Project page: http://visionlab.tudelft.nl/spot