The invention discloses a minimal object measurement
system calibration method based on a general imaging model. A planar coordinate
system is established on the plane of a calibration board, three calibration board images of different attitudes are obtained by a camera and then are subjected to
deblurring, and pixel coordinates of a center of circle are obtained by
ellipse fitting. The method also comprises steps that (3) a general imaging model is used to find a corresponding light equation on a world coordinate
system of each pixel of the images obtained by the camera; (4) a phase position of the calibration board is obtained through an eight-step phase shifting method and a
Gray code method, the coordinates of the center of circle obtained by the camera are matched with the coordinates of the center of circle of a
projector according to the phase position, and a light equation of the
projector, corresponding to each pixel, is obtained using the same method adopted by (3); and (5) an intersection point of light found in the camera and the
projector of each pixel is computed to obtain three dimensional coordinates of an object. The invention improves the general imaging model, enables equipment to be simple and easy to implement, and gets rid of restrictions of a displacement bench in acquisition of the precise displacement.