Abstract: Aiming to the misalignment of the perspective projection of the circle center and the imaged ellipse center when the circle surface and the image plane are not parallel,an analysis method for the projection error of ellipse center was proposed.The mathematical formulation of the projection error was deduced by building the mapping relation between image plane and circle surface,and the factors influencing the error were analyzed by the computer simulation.The method provides a valuable reference in theory for the measurement error evaluation of the circular center and the camera planning,and is valuable in engineering applications of vision measurement.

Key words: Computer vision, Vision measurement, Projection error of ellipse center