Patent ID: 7012199

Claim:
A coordinates correction apparatus comprising: coordinate input means being placed on a display unit; display control means for controlling display of a plurality of reference points on the display unit, the reference points indicating positions for use in calculating coordinates correction parameters, wherein said coordinate input means inputs a coordinate corresponding to one of the displayed reference points based on a user designation; coordinate reception means for receiving the coordinate input by said coordinate input means corresponding to the one of the displayed reference points; discriminating means for discriminating, among the displayed reference points, a reference point corresponding to the coordinate received by said coordinate reception means; coordinates keeping means for keeping the coordinate receiving by said coordinate reception means as the coordinate corresponding to the reference point discriminated by said discriminating means; repeating means for repeating processes of said display control means, said coordinate reception means, said discriminating means and said coordinates keeping means to obtain coordinates for remaining reference points for which a coordinate is not kept by said coordinates keeping means, wherein said display control means is controlled to display only the remaining reference points; parameter calculation means for calculating coordinates correction parameters for nonlinear conversion, based on the coordinates kept by said coordinate keeping means; parameter keeping means for keeping the calculated coordinates correction parameters for nonlinear conversion; and coordinates correction means for correcting the coordinates input via said coordinates input means by the nonlinear conversion using the calculated coordinates correction parameters.