Active Calibration of Camera-Projector Systems Based on Planar Homography

This paper presents a simple and active calibration technique of camera-projector systems based on planar homography. From the camera image of a planar calibration pattern, we generate a projector image of the pattern through the homography between the camera and the projector. To determine the coordinates of the pattern corners from the view of the projector, we actively project a corner marker from the projector to align the marker with the printed pattern corners. Calibration is done in two steps. First, four outer corners of the pattern are identified. Second, all other inner corners are identified. The pattern image from the projector is then used to calibrate the projector. Experimental results of two types of camera-projector systems show that the projection errors of both camera and projector are less than 1 pixel.