New York: Computer scientists have developed a video privacy software that helps prevent inadvertent disclosure of trade secrets and other restricted information within a camera's field of view by letting users specify what others can see. "There are more and more cameras every year. They are incredibly useful," said Landon Cox of Duke University in North Carolina. "But the downside is we're now converting large swaths of our surroundings to a digital format that's easy to access and share, including things we might not want to be digitising," he added. Instead of relying on a developer's best guesstimate of which objects should be "public" and which should be "private", Cox's team set things up so that the user makes that determination. And instead of choosing what to hide, the user chooses what to reveal. The researchers presented two examples of their approach at the 14th International Conference on Mobile Systems, Applications, and Services (MobiSys 2016) in Singapore on Tuesday. One is designed to protect sensitive information on two-dimensional surfaces such as whiteboards and computer presentation slides. The other safeguards images of three-dimensional objects such as keyboards and faces. In both cases, users select the part of a scene that is okay to share by drawing a rectangular border around it, either by hand or with a few clicks of a mouse. Once it knows what it's looking for, the software intercepts all incoming frames from the video stream and rapidly scans frame by frame for a match using computer vision technology. Only authorised objects are allowed to pass from the camera to third-party software, like smartphone apps. Everything else is blocked out by default.