Automatic calibration of a projector-camera system with a see-through screen

This paper proposes a method for automatic calibration of a projector-camera system with a see-through screen. Conventional projector-camera systems usually project a calibration pattern on an opaque screen for calibrating the system. Images captured by the camera contain only the calibration pattern. Recently, projector-camera systems with see-through screen have been developed for visual collaboration. Due to the semi-transparent property of the see-through screen, not only the calibration pattern, but also the background on the opposite side of the screen is captured by the camera. Since the calibration pattern is contaminated by the image of the background, conventional feature detection methods have difficulty in detecting the features of the calibration pattern and thus often fail to calibrate the system. In the proposed methods, the calibration pattern is temporally varied so that temporal correlation can be applied on a sequence of captured images to separate the calibration pattern from the background. This method works robustly and accurately even for backgrounds with high dynamic range and large motion. The entire calibration process is fully automatic and does not require any parameter tuning.