A Theory for Photometric Self-Calibration of Multiple Overlapping Projectors and Cameras

A theory for photometric calibration of cameras and multiple projectors with overlapping displays is presented. The theory is predominantly based on the analysis of isointensity curves in projector input state space curves which define different projector input intensity combinations that result in the same camera-observed pixel intensities. Three methods, which have different speed and accuracy tradeoffs, are proposed for recovering the projector-to-screen and screento- camera intensity transfer functions. The methods do not require a specific parametric model for the shapes of these functions, nor impose any smoothness constraints. Additional methods are described for calibrating projector offsets and binary light sources, and also extending the perpixel analysis to other pixels in the display. The methods do not require the use of expensive equipment, and may be carried out with a low dynamic range camera with minimal controls.