Geometrical Privacy Protection Tool

Pavel Korshunov Touradj Ebrahimi

EPFL, Switzerland

Challenges §  Keep the balance between

-  Privacy and intelligibility -  Privacy and appropriateness

§  Make the protection reversible §  How to protect different regions?

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Reversible protection 1 •  Body

silhouettes

•  Warping protection

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Reversible protection 2 •  Faces and

accessories

•  Morphing protection

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Standard face Face to protect

Morphed result

Use this face instead of the original

Triangulation points Morphing parameters���

Algorithm Standard face���

Recovered

Making pleasant •  Morph – Faces to smileys – Backpack – Bag

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Evaluation results

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51  

73.2  

23.6  

61.6  67.7  

40.7  

57.3   59.5  

46.3  

0 10 20 30 40 50 60 70 80 90

100

Privacy Intelligibility Appropriateness Crowdsourcing Stakeholders Practitioners

Conclusions •  Privacy is high •  Intelligibility is OK •  Professional evaluators do not like it

•  Who does not like a smiley?

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