CRT image distortion determination experiment

An analytical photogrammetric approach was used to determine the geometric distortions of cursor coordinates on an image viewing and measuring system which included a television camera, the associated electronics and a cathode ray tube display. Computer programs were developed to provide the determination of common lens distortion parameters, the camera orientation and additional distortions due to the electronic components, all in several combinations. Measurements made with the use of a calibrated grid were processed through a least squares solution. The mathematical formulation of the various error types can be used to determine the respective errors completely, but not in a single simultaneous solution. Independent determinations of electronic distortion and camera position must be used and coordinate mensuration errors should be monitored and minimized.