Alharbi Rawan, Tolba Mariam, Petito Lucia C, Hester Josiah, Alshurafa Nabil
Northwestern University.
Proc ACM Interact Mob Wearable Ubiquitous Technol. 2019 Sep;3(3). doi: 10.1145/3351230.
Activity-oriented cameras are increasingly being used to provide visual confirmation of specific hand-related activities in real-world settings. However, recent studies have shown that bystander privacy concerns limit participant willingness to wear a camera. Researchers have investigated different image obfuscation methods as an approach to enhance bystander privacy; however, these methods may have varying effects on the visual confirmation utility of the image, which we define as the ability of a human viewer to interpret the activity of the wearer in the image. Visual confirmation utility is needed to annotate and validate hand-related activities for several behavioral-based applications, particularly in cases where a human in the loop method is needed to label (e.g., annotating gestures that cannot be automatically detected yet). We propose a new type of obfuscation, , as a methodological contribution to researchers interested in obtaining visual confirmation of hand-related activities in the wild. We tested the effects of this approach by collecting ten diverse and realistic video scenarios that involved the wearer performing hand-related activities while bystanders performed activities that could be of concern if recorded. Then we conducted an online experiment with 367 participants to evaluate the effect of varying degrees of obfuscation on bystander privacy and visual confirmation utility. Our results show that activity-oriented partial obfuscation (1) maintains visual confirmation of the wearer's hand-related activity, especially when an object is present in the hand, and even when extreme filters are applied, while (2) significantly reducing bystander concerns and enhancing bystander privacy. Informed by our analysis, we further discuss the impact of the filter method used in activity-oriented partial obfuscation on bystander privacy and concerns.
以活动为导向的摄像头越来越多地被用于在现实场景中提供与手部特定活动相关的视觉确认。然而，最近的研究表明，旁观者对隐私的担忧限制了参与者佩戴摄像头的意愿。研究人员已经研究了不同的图像模糊处理方法，作为增强旁观者隐私的一种途径；然而，这些方法可能会对图像的视觉确认效用产生不同的影响，我们将视觉确认效用定义为人类观察者解读图像中佩戴者活动的能力。对于一些基于行为的应用，特别是在需要人工标注（例如，标注尚未能自动检测到的手势）的情况下，手部相关活动的标注和验证需要视觉确认效用。我们提出了一种新型的模糊处理方法，作为对那些希望在自然环境中获得手部相关活动视觉确认的研究人员的方法学贡献。我们通过收集十个不同且逼真的视频场景来测试这种方法的效果，这些场景中佩戴者进行与手部相关的活动，而旁观者进行的活动如果被记录可能会引起关注。然后，我们对367名参与者进行了一项在线实验，以评估不同程度的模糊处理对旁观者隐私和视觉确认效用的影响。我们的结果表明，以活动为导向的部分模糊处理（1）能够保持对佩戴者手部相关活动的视觉确认，尤其是当手中有物体时，即使应用了极端滤镜也是如此，同时（2）显著降低了旁观者的担忧并增强了旁观者的隐私。根据我们的分析，我们进一步讨论了以活动为导向的部分模糊处理中使用的滤镜方法对旁观者隐私和担忧的影响。
