SharpView: Improved Clarity of Defocused Content on Optical See-Through Head-Mounted Displays
Augmented Reality (AR) systems, that utilize optical see-through head-mounted displays, are becoming more common place, with several consumer level options already available, and the promise of additional, more advanced devices on the horizon. A common factor among current generation optical see-through devices, though, is fixed focal distance to virtual content. While having a fixed focus is not a concern for video see-through AR, since both virtual and real world imagery are combined into a single image by the display, unequal distances between real world objects and the virtual display screen in optical see-through AR is unavoidable.
In this thesis, we investigate the issue of focus blur, in particular, the blurring caused by simultaneously viewing virtual content and physical objects in the environment at differing focal distances. We also examine the application of dynamic sharpening filters as a straight-forward, system-independent means for mitigating this blurring effect, thereby improving the clarity of defocused AR contents. We assess the utility of our method, termed SharpView, by employing an adjustment experiment in which users actively apply varying amounts of sharpening to reduce the perception of blur in AR content shown at four focal disparity levels relative to real world imagery. In addition, as a confirmation of practicality, we validated SharpView in an AR matching task.
Our experimental results confirm that dynamic correction schemes are required for adequately addressing the presence of blur in Optical See-Through AR. Also we got a finding that while users are sensitive to the perceptual effects of focal disparity, their performance in an AR matching task was not negatively impacted even in the presence of significant blur. Through the experiments, we validate the ability of our SharpView model to improve the perceived visual clarity of blurred content, with optimal performance at focal differences well-suited for near-field AR applications.