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Calibrating Scalable Multi-Projector Displays Using Camera Homography Trees

We present a practical vision-based calibration system for large format multi-projector displays. A spanning tree of homographies, automatically constructed from several camera images, accurately registers arbitrarily-mounted projectors to a global reference frame. Experiments on the 18’ 8’ Princeton Display Wall (a 24 projector array with 6000 3000 resolution) demonstrate that our algorithm achieves sub-pixel accuracy even on large display surfaces. A direct comparison with the previous best algorithm shows that our technique is significantly more accurate, requires far fewer camera images, and runs faster by an order of magnitude.