Achieving seamlessness in multi-projector based tiled display using camera feedback

High resolution displays utilizing an array of commodity projectors are becoming popular approach(also called tiled displays) for visualizing high resolution content like scientific data-sets. These systems provide a relatively cheaper and flexible alternative to displays based on single high resolution monitor or projector. This approach inherently provides a method to create displays with resolution much higher than that possible by using a single high resolution display device. However, bezels in monitor based tiled displays obstruct the geometric continuity of the rendered content. In this paper, we describe the algorithms for geometric alignment of projection regions of an array of arbitrarily placed projectors and attenuation of projected intensities in the overlapping regions of multiple projectors using camera as a feedback device. Combination of these algorithms help us achieve a seamless high resolution display. We have observed improvements in fidelity of the rendered content by utilizing collinearity constraint in geometric alignment calculations. We also propose a novel technique based on cross-ratio invariant for utilizing full projection region of individual projectors which was limited by the size of features used for geometric alignment in the earlier approaches for planar displays. This also results in more imperceptible edge blending artifacts for same physical setup of projectors.