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These privacy-preserving optics filter or modulate light before it reaches the sensor of time-of-flight cameras, preserving the privacy of subjects seen on live camera feeds and recordings without impacting depth quality. The video surveillance, gesture recognition and depth sensing market size in total is expected to exceed $25 billion by 2016. Surveillance of the public is ever-increasing as cameras are used for new applications such as motion tracking for video games, webcam communication, and people counting. An important concern as surveillance becomes more universal among the public is the liability of the recorder for invading a citizen’s right to privacy by identifying them. Researchers at the University of Florida have developed a computational theory of privacy-preserving optics that blurs or blocks incoming light before it reaches cameras. For example, these optics can be applied to cameras with publicly accessible feeds, cameras inside the home (blocking incoming light when the camera is intended to be off), or image-processing devices where high resolution images are not required. In each situation, these optics preserve the privacy of subjects at very low cost without impacting camera function.
Optics that maintain the privacy of recorded individuals by modulating incoming light to time-of-flight sensors
These simple optics can be constructed into sensors to help maintain the privacy of image subjects. They consist of multiple apertures with blurring lenses and/or a blank-out panel that completely blocks incoming light. By attaching these to multi-sensor devices or depth sensors, the total privacy of the cameras/sensors is increased at very little cost. Because of the way the defocus is designed, the depth sensing capability of the time-of-flight cameras
This eye scan security feature removes iris signatures from the digital images used in eye-tracking devices. Eye-tracking functionality will enable many features in the next generation of automobiles, educational hardware, and more. Mixed and virtual reality headsets already use integrated eye trackers in which cameras image the user's eye to detect gaze location and pupil diameter. While this functionality is intended to improve the quality of the user’s experience, built-in eye trackers pose a security threat. Hackers would gain access to a high-resolution image of the user's iris that could potentially breach secure authentication in applications such as banking and voting.
Researchers at the University of Florida have developed a low-cost security step that degrades iris authentication while still allowing accurate gaze tracking in mixed reality headsets and other devices using eye-tracking. The security feature can either defocus the iris in the imaging process or add randomized visual noise to the iris image. Both implementations remove the high frequency identifying features of the iris while preserving the low-frequency components necessary for gaze estimation in applications from gaming to internet security.
Security feature for eye-tracking devices that protects users from spoofing attacks or identity theft by removing iris detail in eye scan images
This eye scan security improvement introduces optical defocus to the iris image. Doing so retains the pupil tracking ability of an eye-tracking device while removing high frequency identifying biometric details. An image processing module in a device’s software or a modification of its hardware implements the iris defocusing. Likewise, introducing pixel noise to the image removes a user’s biometric signature. An algorithm randomly selects a percentage of pixels in the iris image and sets them to a constant value, digitally degrading the image. Adding this random noise to the image adds a layer of encryption for contexts requiring a greater level of security.
This optical coherence tomography (OCT) probe uses an electrothermal microelectromechanical systems (MEMS) mirror kept in liquid to increase the optical scan range and shock resistance of OCT probes. OCT is a medical imaging technique that captures real-time, cross-sectional images from within tissue, which is vital for detecting cancers early, since most originate from within internal organs. OCT eliminates the risk of ionizing radiation, a problem with available imaging techniques, and produces high resolution images revealing detail down to micrometers. Electrothermal MEMS mirrors are useful in endoscopic OCT image probes because of their small size, high fill factor and low driving voltage. These mirrors, however, only offer a 60-degree scanning angle. This poses a problem in the case of bronchial scans, for example, which require a 360-degree full circumferential optical scan. Available MEMS OCT probes require multiple insertions of the probe inside the trachea in order to capture a full circumferential optical scan, which causes significant pain or discomfort for patients. To address this, University of Florida researchers have developed a MEMS OCT imaging probe that scans a full internal circumference in one insertion. The MEMS mirror immersed in liquid produces a Snell's window effect that amplifies the optical scan range and increases the shock resistance of the probe.
An OCT probe with a broad scanning angle that can capture a full-circumferential image of a tubular organ such as the bronchi with only one insertion
Available MEMS mirrors cannot work properly in liquid. The mirrors developed by University of Florida researchers have a large gap under the mirror plate in the substrate, which allows liquid to fill in while reducing the squeeze-film damping. The gap also allows the mirror plate to rotate in the liquid without causing stiction. When these mirrors are kept in liquid, the refraction of the light through the liquid creates a Snell’s effect that significantly amplifies the optical scan angle. This effect is very similar to the effect of a fisheye lens, and allows an OCT probe to view a full-circumferential image of a bronchi or other tubular organ with only one insertion into the patient.
