MediaEval 2015 - MediaEval 2015 Drone Protect Task: Privacy Protection in Surveillance Systems Using...
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Transcript of MediaEval 2015 - MediaEval 2015 Drone Protect Task: Privacy Protection in Surveillance Systems Using...
MediaEval 2015 Drone Protect Task:Privacy Protection in Surveillance Systems
Using False Coloring
Serdar Çiftçi1, Pavel Korshunov2, Ahmet Oguz Akyüz1, TouradjEbrahimi2
1. Middle East Technical University, Ankara, Turkey2. Ecole Polytechnique Fedéralé de Lausanne, Switzerland
MEDIAEVAL 2015 Drone Protect Task
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 1 / 18
Outline
1 Introduction
2 Related Work
3 False Color Based Privacy Protection
4 Experiments
5 Conclusion
6 References
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 2 / 18
Introduction
Video Surveillance Systems Surround Us
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 3 / 18
Related Work
Most Used Methods
Figure taken from [KMDE13].
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 4 / 18
Related Work
Warping
Figure taken from [KE13b].
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 5 / 18
Related Work
Morphing
Figure taken from [KE13a].
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 6 / 18
Related Work
Scrambling
Figure taken from [DE08].
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 7 / 18
Related Work
In-Painting
Figure taken from [CVP+09].
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 8 / 18
False Color Based Privacy Protection
Privacy Protection in Surveillance Systems Using False Coloring
Why we need a novel method?
Most methods are computer vision techniques dependent.
There is a trade off between privacy protection and intelligibility.
Reversibility may not be possible.
Pleasantness is an important issue.
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 9 / 18
False Color Based Privacy Protection
Privacy Protection in Surveillance Systems Using False Coloring
The main steps are as follows:
Convert a color frame into grayscale.
Pixel intensities of the grayscaled frame are then used as keys toa look-up table that represents a color palette.
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 10 / 18
False Color Based Privacy Protection
Privacy Protection in Surveillance Systems Using False Coloring
Reverse function steps are as following:Perform an inverse table look-up.
Reversion is only possible if one knows the properties of the colormap used during protection.
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 11 / 18
Experiments
Used Color Palettes
LOCS RBS
DEF
LOCS: Linearized optimal color scale (for Low Level Privacy)RBS: Rainbow color scale (for Medium Level Privacy)DEF: Radiance default color scale (for High Level Privacy)
Selection of the color palettes are based on our previous work published at SPIE Human Visionand Electronic Imaging XX 2015 conference.Using false colors to protect visual privacy of sensitive content,Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi.
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 12 / 18
Experiments
Example Results
Figure : False color results, a) original frame, c) protected frame, e)recovered frame.
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 13 / 18
Experiments
Subjective Evaluation Results
Privacy Intelligibility PleasantnessFC AVG FC AVG FC AVG
Expert 0.39 0.49 0.76 0.59 0.73 0.60Naïve 0.34 0.48 0.75 0.58 0.75 0.61
Average 0.365 0.49 0.755 0.59 0.74 0.60
Table : Evaluation results where FC and AVG respectively stand for falsecolor results and the average of all submissions. Expert and Naïve’s areparticipant groups which represent the people conducting research on visualprivacy protection and naïve observers.
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 14 / 18
Conclusion
Findings and Future Work
We described a simple and effective method for protecting privacyusing false coloring.Benchmarking evaluations indicated higher than average score forpleasantness and intelligibility.However, the privacy protection level was found to be lower thanaverage.Future work will investigate designing custom color scales toimprove privacy protection and the quality of reversibility whileenhancing security.
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 15 / 18
Conclusion
Thank you!
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 16 / 18
References
References I
[CVP+09] S-CS Cheung, MV Venkatesh, JK Paruchuri, J Zhao, andT Nguyen, Protecting and managing privacy information invideo surveillance systems, Protecting Privacy in VideoSurveillance, Springer, 2009, pp. 11–33.
[DE08] Frederic Dufaux and Touradj Ebrahimi, Scrambling forPrivacy Protection in Video Surveillance Systems, IEEETrans. on Circuits and Systems for Video Technology vol.18 (2008), no. no. 8, 1168–1174.
[KE13a] Pavel Korshunov and Touradj Ebrahimi, Using FaceMorphing to Protect Privacy, IEEE InternationalConference on Advanced Video and Signal-BasedSurveillance (AVSS), 2013.
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 17 / 18
References
References II
[KE13b] , Using Warping for Privacy Protection in VideoSurveillance, 18th International Conference on DigitalSignal Processing (DSP), 2013.
[KMDE13] Pavel Korshunov, Andrea Melle, Jean-Luc Dugelay, andTouradj Ebrahimi, A framework for objective evaluation ofprivacy filters in video surveillance, Proceedings of SPIEVolume 8856 (San Diego, California, USA), Spie-Int SocOptical Engineering, 2013.
Serdar Çiftçi, Pavel Korshunov, Ahmet Oguz Akyüz, Touradj Ebrahimi (METU-EPFL)False Coloring for Visual Privacy September 15th 2015 18 / 18