Patent ID: 7137707
Filing Date: 2006-11-21
Classification: G03B,H04N

Abstract:
1. A method for determining a projector pixel that is related by pinhole projection to a laser point on a display surface, comprising: projecting a laser point onto a display surface with a laser pointer; viewing the laser point with a camera in a fixed relationship with respect to the laser pointer and with respect to a projector, in which the laser pointer and the camera are mounted rigidly on the projector; projecting a set of projector points onto the display surface with the projector; viewing the set of projector points with the camera; determining a planar homography between the camera and projector defined by a correspondence between the projector points in a projector image plane and the projector points in a camera image plane; using the planar homography to transform the laser point from the camera image plane to the projector image plane as transformed laser points; determining a location of a first line in the camera image plane passing through the set of laser points acquired as a distance varies between the laser pointer and the display surface; determining a location of a second line in the projector image plane passing through the set of transformed laser points acquired as the distance varies between the laser pointer and the display surface; determining a line homography between the first line and the second line using the laser points and the corresponding transformed laser points; viewing a subsequent laser point with the camera, and using the line homography to transform the subsequent laser point to the projector image plane to determine a location of a pixel on the projector image plane related by pinhole projection to the subsequent laser point on the display surface, in which the pixels are set to give a fixed projection on the display surface while the projector is moving.