Image projection device for 3D measurement and calibration method for calibration of camera and projector

An image projection device, comprising:

• a camera;
• a projector configured to:
• project a first image;
• and
• project structural light on a checker pattern;
• and
• circuitry configured to:
• calibrate the camera;
• ray trace the checker pattern;
• determine first distortion parameters of the projector based on evaluation of a distortion amount, wherein the distortion amount is based on a group of lattice points of the checker pattern, wherein the group of lattice points of the checker pattern constitutes a straight line on projector coordinates;
• determine a first correspondence relation between a first lattice point of the group of lattice points of the checker pattern and the projector coordinates, and a second correspondence relation between a second lattice point of the group of lattice points on a second image of the checker pattern after distortion correction and world coordinates;
• determine internal parameters of the projector and external parameters of the projector, based on the first correspondence relation;
• and
• determine a first perspective projection matrix that includes the internal parameters and the external parameters of the projector by first nonlinear optimization, based on the second correspondence relation;
• and
• generate a corrected image based on correction of the first image projected from the projector, wherein the first image projected from the projector is corrected based on at least one of the determined internal parameters, the determined external parameters, or the determined first distortion parameters.