Local Methods for Measuring Tiled Display Alignment

We describe a new method for accurately measuring the relationship between pixel coordinates of neighboring projectors in a tiled projection display. The method can be used to calibrate the alignment and distortions in the tiled display and to touch up existing calibrations with local corrections. Additionally, by simultaneously measuring the characteristic spacing of textural features on the screen surface, we show how an absolute measure of the screen coordinates might be derived. The techniques have application to information encoding in images, in situ measurement of projector distortions without interrupting display of image content, and commodity tile-aware smart projectors. We discuss the limits to precision of these measurements.