Implementation of on-site virtual time machine for mobile devices

In this study, we developed a system for mobile devices designed to provide a virtual experience of past scenery depicted in old photographs by superimposing them on landscapes in video see-through frames. A user is asked to capture a photograph of a landscape to be used as a keyframe and enter correspondence points between the new and old photos. The old photograph is deformed by projective transform with homography computed based on correspondence points. We then superimpose of the old photograph onto video see-through frames of current landscape. To achieve real-time and robust superimposition on mobile devices, both motion-sensor-based pose information and camera-image-keypoint-tracking-based pose information is used for device´s camera pose tracking.