  We live and work in environments that are inundated with cameras embedded in
devices such as phones, tablets, laptops, and monitors. Newer wearable devices
like Google Glass, Narrative Clip, and Autographer offer the ability to quietly
log our lives with cameras from a `first person' perspective. While capturing
several meaningful and interesting moments, a significant number of images
captured by these wearable cameras can contain computer screens. Given the
potentially sensitive information that is visible on our displays, there is a
need to guard computer screens from undesired photography. People need
protection against photography of their screens, whether by other people's
cameras or their own cameras.
  We present ScreenAvoider, a framework that controls the collection and
disclosure of images with computer screens and their sensitive content.
ScreenAvoider can detect images with computer screens with high accuracy and
can even go so far as to discriminate amongst screen content. We also introduce
a ScreenTag system that aids in the identification of screen content, flagging
images with highly sensitive content such as messaging applications or email
webpages. We evaluate our concept on realistic lifelogging datasets, showing
that ScreenAvoider provides a practical and useful solution that can help users
manage their privacy.
