UNIZA@Mediaeval 2014 Visual Privacy Task: Object Transparency Approach
Overview of the MediaEval 2014 Visual Privacy Task
-
Upload
multimediaeval -
Category
Software
-
view
37 -
download
0
Transcript of Overview of the MediaEval 2014 Visual Privacy Task
Visual Privacy Task Overview
Atta Badii, Touradj Ebrahimi, Christian Fedorczak, Pavel Korshunov,Tomas Piatrik, Volker Eiselein, Ahmed Al-Obaidi
Task Description
• To explore the possibilities to optimise the process of privacy filtering so as to:
1. obscure personal visual information effectively
whilst,
2. keeping as much as possible of the ‘useful’ information that would enable a human viewer to interpret the obscured video frame.
Slide 2
Participants
VPT 2014: VPT 2014: 1111 registrations, registrations, 88 participants participants , ,
PEViD Dataset
21 annotated videos• ~20s• 25fps• 1920x1080• Indoor/Outdoor • Daytime/Evening • Featured actions include: Bag dropping, Pickpocketing, Fighting,
or simply Walking • Ground truth consists of: annotated People, Faces, Accessories,
Hair regions, Skin regions
Development Set = 9 videos
Evaluation Set = 12 videos
Privacy sensitive region
Sensitivity level
Skin Medium (M)Face High (H)Hair Low (L)Accessories Medium (M)Person Low (L)
Subjective Evaluation Streams
The privacy protected video clips were evaluated by each of three distinct communities of human evaluators:
i) Naive viewers (engaged via a crowdsourcing platform)• 290 workers responded, 230 were found to have provided
reliable responses
ii) Video-analytics technology and privacy protection solutions developers
• focus group consisted of (65) participants, (15) of them were females
iii) Surveillance monitoring staff and law enforcement staff• focus group comprised of (59) participants including (22)
females
Slide 5
Evaluation Setup
• Six (6) video clips were pre-selected from each submission and evaluated using the three (3) evaluation streams.
• A Questionnaire consisting of 12 questions had been carefully designed to examine aspects related to privacy, intelligibility, and pleasantness; this was used in stream 2 and 3.
• The First (5) questions were aimed at eliciting the opinions of the evaluators re the Contents of the viewed videos. The responses to these questions were considered with respect to the ground truth.
• The rest of the questions were aimed at eliciting the Subjective Opinions of the evaluators re the viewed videos.
• Stream 1 used a shortened version of the questionnaire with (7) questions in total due to crowdsourcing constraints.
Slide 6
UI-REF based criteria
• Privacy Protection Level – How adequate was the level of privacy protection achieved by the filter across all testing video clips?
• Level of Intelligibility – How much ‘useful’ information that was retained in the video frames after privacy filtering had been applied?
• Pleasantness of the resulting privacy filtered video frames in terms of their ‘aesthetic’ perceptual appeal to human viewers. How acceptable were any adverse aesthetic effects?
Perceived Effects, Side Effects, Cross-Effects, Affects
Slide 7