Patent ID: 6292171
Filing Date: 2001-09-18
Classification: G06F,G09G,H04N

Abstract:
A method for correlating the projection coordinates Q(x.sub.Q,y.sub.Q) of image elements projected onto a surface to the display coordinates P(x.sub.P,y.sub.P) of the corresponding image elements as displayed on a computer screen, said method comprising the steps of:generating a set of n calibration spots disposed in a nonlinear pattern within the displayed image, where n.gtoreq.4, the predetermined coordinates of said calibration spots denoted by P.sub.i (x.sub.P,y.sub.P), where 1.ltoreq.i.ltoreq.n, each said calibration spot having a brightness greater than a predetermined threshold level;projecting the displayed image and said calibration spots onto the projection surface so as to form a calibration image thereon, said calibration image comprising n bright clusters corresponding to said n calibration spots;determining the projection coordinate of the mean position Q.sub.i (x.sub.Q,y.sub.Q) of each of said n bright clusters; and,deriving transformation coefficient matrices A and B by solving the set of vector equations given by:Q.sub.1 =AP.sub.1 +BQ.sub.2 =AP.sub.2 +BQ.sub.n ={dot over ({dot over (A)})}P.sub.n +Bsuch that the display coordinate P.sub.k (x.sub.P,y.sub.P) of a displayed image element can be determined from the projection coordinate Q.sub.k (x.sub.Q,y.sub.Q) of the corresponding projected image element by means of the conversion equationQ.sub.k =AP.sub.k +B.