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Overview of MediaEval 2012 Visual Privacy Task

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Overview of MediaEval 2012 Visual Privacy Task

  1. 1. Visual Privacy Task OverviewTomas Piatrik, Queen Mary University of LondonAtta Badii, University of Reading
  2. 2. Task Description• Visual privacy protection of people occurred in a video taking into consideration the acceptability and attractiveness of the resulting obscured or scrambled region.
  3. 3. Data200 videos• 30s-90s• 25fps, 30fps• 640x480, 704x576• Daytime• Evening• People wearing accessories (hat, scarf, sunglasses)Evaluation Set – 12 videos (4 per each category)
  4. 4. Evaluation Methodology1. Objective Evaluation• Accuracy of the bounding boxes• Anonymity – evaluated by automatic face detection• Intelligibility – evaluated by object tracking• Quality: SSIM & PSNR – similarity between the original and obscured images2. User Study (subjective evaluation)• 20 subjects• 2-range score (0,1; 0-0,5-1)
  5. 5. User StudyQuestionnaires • General Evaluation • Clip Evaluation - cropped obscured face • Clip Evaluation – whole frames
  6. 6. User StudyQuestionnaire: • Is the person of interest wearing sunglasses? … • What is the person’s gender? • What is the person’s ethnicity? • Is it possible to guess the person’s facial expression? • Is the masking hiding sufficient features? • Do you feel that this masking technique could protect your identity if used on CCTV systems? • Do you find the masking effect distracting? • Do you find the masking effect irritating? • …
  7. 7. Results – objective evaluationParticipants: co-organising teamObjective evaluation: Accuracy Anonymity Intelligibility SSIM PSNR EPFL 0.24 1.00 0.85 0.92 28.26 Eurecom 0.37 1.00 0.82 0.93 32.89 UoR 0.50 1.00 0.93 0.96 35.80
  8. 8. Results – User Study
  9. 9. Results – User Study
  10. 10. Thank You

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