A high-accuracy three-dimensional reconstruction method based on projection beam calibration using a high-accuracy three-dimensional reconstruction system based on projection beam calibration, applied to a projection apparatus provided with a microelectromechanical system (MEMS) polarizer or a digital micromirror device (DMD) module, the high-accuracy three-dimensional reconstruction system based on projection beam calibration including an imaging apparatus calibration unit, a unidirectional absolute phase distribution diagram acquisition unit, an epipolar line fitting unit, a plane parameter equation calculation unit, a projection beam fitting unit, a projection mapping coefficient lookup table setup unit and a spatial three-dimensional point coordinate acquisition unit,
- the high-accuracy three-dimensional reconstruction method based on projection beam calibration comprising the following steps:
- the imaging apparatus calibration unit performing calibration on an imaging apparatus;
- the unidirectional absolute phase distribution diagram acquisition unit projecting patterns to a planar target at different positions by using the projection apparatus, acquiring each target image of the planar target by using the imaging apparatus, and calculating each unidirectional absolute phase distribution diagram of the planar target;
- the epipolar line fitting unit establishing the imaging apparatus coordinate system with the optical center of the imaging apparatus as the point of origin and an optical axis of the imaging apparatus as Z axis, calculating each plane parameter equation of the planar target in the imaging apparatus coordinate system, using an absolute phase of the planar target at a designated position as a standard phase, searching each unidirectional absolute phase distribution diagram for first subpixels having a phase which is the same as the standard phase, converting the first subpixels into points in a normalization plane, and fitting corresponding epipolar lines in the normalization plane;
- wherein the epipolar line fitting unit includes the plane parameter equation calculation unit, and the plane parameter equation calculation unit is configured to calculate each plane parameter equation of the planar target in the imaging apparatus coordinate system, and acquire each coordinate expression of the planar target in the imaging apparatus coordinate system by using a formula Πc=H−T·Πw, wherein Πw=(0,0, 1, 0)T is an expression of the planar target in a world coordinate system, T represents a transpose of a matrix, and His rigid transformation from the world coordinate system into the imaging apparatus coordinate system,
- the projection beam fitting unit calculating intersections between the corresponding planar target and rays formed by all points on each epipolar line in the normalization plane and the optical center of the imaging apparatus, and fitting a corresponding projection beam by using the intersections;
- wherein the calculating intersections between the corresponding planar target and rays formed by all points on each epipolar line in the normalization plane and the optical center of the imaging apparatus, and fitting a corresponding projection beam by using the intersections includes the following steps:
- all points on the epipolar line in the normalization plane and the optical center of a camera form corresponding rays, and each ray and a corresponding plane parameter equation are joined, so that spatial points on the corresponding planar target can be acquired, and next the spatial points are used to fit a corresponding projection beam,
- the projection mapping coefficient lookup table setup unit establishing a projection mapping coefficient table according to position relationships between the projection beam and the points in the normalization plane;
- and
- spatial three-dimensional point coordinate acquisition unit projecting a pattern to an object under test by using the projection apparatus, acquiring an object image of the object under measurement by using the imaging apparatus, calculating a unidirectional absolute phase distribution diagram of the object image, searching the projection mapping coefficient table for projection mapping coefficients corresponding to absolute phases in the unidirectional absolute phase distribution diagram of the object image, and calculating corresponding spatial three-dimensional point coordinates by using the projection mapping coefficients.