Improving relative depth judgments in augmented reality with auxiliary augmentations

Significant depth judgment errors are common in augmented reality. This study presents a visualization approach for improving relative depth judgments in augmented reality. The approach uses auxiliary augmented objects in addition to the main augmentation to support ordinal and interval depth judgment tasks. The auxiliary augmentations are positioned spatially near real-world objects, and the location of the main augmentation can be deduced based on the relative depth cues between the augmented objects. In the experimental part, the visualization approach was tested in the “X-ray” visualization case with a video see-through system. Two relative depth cues, in addition to motion parallax, were used between graphical objects: relative size and binocular disparity. The results show that the presence of auxiliary objects significantly reduced errors in depth judgment. Errors in judging the ordinal location with respect to a wall (front, at, or behind) and judging depth intervals were reduced. In addition to reduced errors, the presence of auxiliary augmentation increased the confidence in depth judgments, and it was subjectively preferred. The visualization approach did not have an effect on the viewing time.