High accuracy pixel-wise spatial calibration of optical see-through glasses

摘要

Precisely calibrated optical see-through glasses are the key for many augmented reality applications. Existing works divide the system consisting of a user wearing glasses into a display part and an eye part. The former is calibrated once whereas the eye is adapted continuously. Previous methods either model the optical system using perspective projection or triangulate the pixels' virtual positions. Parametric models are often inadequate in the edge areas of the displays and based on only a few non-equidistant point correspondences recorded by the user. The triangulation approach is improving this by calibrating every pixel individually with camera-based point correspondences. Whereas the previous generation of see-through glasses used simple optics like half-transparent mirrors the latest generation uses more complex optical elements like gratings or free-form light-guides. Minor changes of the viewpoint can cause a viewing ray to pass through the neighboring grating which makes a triangulation of the pixel's virtual position impossible. Another work splits the distortion calibration into a real-world distortion and a display distortion part since the viewing rays pass through different optical elements.