The invention discloses a three-dimensional measurement method and
system based on single
grating projection. The three-dimensional measurement method comprises the steps that a physical
grating is projected to an object to be tested in an out-of-focus manner so as to form a sinusoidal
fringe pattern, and a deformed
fringe pattern of the object to be tested is collected; the deformed
fringe pattern is processed by using an S-transform method to obtain the
principal value phase Phi(x, y); unwrapping is performed based on a wrapping
elimination method to obtain the
absolute phase phi(x, y), and a three-dimensional measurement
system for telecentric imaging is calibrated so as to build an imaging model, and three-dimensional coordinate information of the tested object is calculated. The three-dimensional measurement
system is used for executing the method. The three-dimensional measurement method is based on the single fringe pattern,
zero padding is performed on both ends of the
principal value phase after the
principal value phase is obtained according to the S-transform method so as to acquire up-sampling in the
frequency domain, the
frequency spectrum of the phase is shifted to the original position according to
frequency shift characteristics of
Fourier transform, a phase component of carriers is eliminated, the height-
phase mapping relationship is fitted by adopting the telecentric imaging model, the three-dimensional measurement system is calibrated, the three-dimensional coordinate information of the tested object is obtained, the steps are simple, and the measurement speed is higher.