1 results about "Sinusoidal grating" patented technology

The application provides a three-dimensional measurement method and system based on double-frequency time domain unwrapping, wherein the method comprises the following steps: parameter calibration is performed on an image acquisition device; sinusoidal correction is performed on grating fringes projected by a grating fringe projection device; high and low sinusoidal grating fringes of different frequencies are projected onto the surface of a measured object in sequence, phase shift scanning is performed on each frequency, and deformed images are collected; a maximum light intensity threshold method or a light intensity difference self-determination method is used to identify and process a projection blind area; and three-dimensional coordinates of each point on the surface of the measured object are calculated based on a double-frequency time domain phase unwrapping algorithm, and an STL format three-dimensional data file is generated. The three-dimensional measurement method and system based on double-frequency time domain unwrapping can not only measure discontinuous and mutant surface objects which are difficult to process by traditional methods with high precision, effectively eliminate the pull line phenomenon and noise point interference, but also reduce the number of image collection compared with a three-frequency method, and improve the measurement efficiency.