Non-uniform resampling in perspective compensated large scale 3D visualization

Abstract

The presented work addresses the problem of non-uniform resampling that arises when an image shown on a spatially immersive projection display, such as walls of a room, is intended to look undistorted for the viewer at different viewing angles. A possible application for the proposed concept is in commercial motion capture studios, where it can be used to provide real-time visualization of virtual scenes for the performing actor. We model the viewer as a virtual pinhole camera, which is being tracked by the motion capture system. The visualization surfaces, i.e. displays or projector screens, are assumed to be planar with known dimensions, and are utilized along with the tracked position and orientation of the viewer. As the viewer moves, the image to be shown is geometry corrected, so that the viewer receives the intended image regardless of the relative pose of the visualization surface. The location and orientation of the viewer result in constant recalculation of the projected sampling grid, which causes a non-uniform sampling pattern and drastic changes in sampling rate. Here we observe and compare the ways to overcome the consequent problems in regular-to-irregular resampling and aliasing, and propose a method to objectively evaluate the quality of the geometry compensation.