Three-dimensional Surface Measurement Technology Of Human Body Based On Frequency-doubled Grating Projection

Use the frequency-doubled grating projection technology to measure the three-dimensional shape of the human body.One can solve the unstable problem from the acquisition process of human body three-dimensional surface measurement.The way realized the independent calculation of the height of the sampling points of the sampling points on the surface of the three-dimensional object and solved the problem of cumulative error caused by computation path operation of traditional single spatial frequency grating phase shifting technique.This way improved measurement accuracy and therefore,provided an effective measurement method for 3-D surface measurement of the human body.The main research work is as follows:1.Write a computer program of making projection raster stripes.Using digital image technology to make sinusoidal distribution raster images of different spatial frequencies.2.The three-dimensional surface measurement system for frequency-doubled grating projection is established.A series of frequency-doubled sinusoidal grating strips at different spatial frequencies are sequentially projected onto the surface of the human body,forming a stripe image deformed with the surface of the human body on the surface of the human body.The image acquisition system sequentially synchronizes the high-speed photographing of the fringe image of the human body surface by using the synchronous triggering device.3.Write a calculation program for 3-D surface measurement of the frequency-doubled grating projection.A four-step phase-shifting fringe image of the same spatial frequency was used to calculate the parcel phase,calculating the unfolded phase of each frequency from the unwrapped expansion phase of the lowest frequency.Finally the expansion phase at highest frequency is achieved,which is the relative height distribution image of the three-dimensional profile of the human body.Combining the relationship between phase and height,The height value corresponding to the calibration point can be obtained.According to this method,the three-dimensional shape of the human body can be reconstructed by performing repeated calculations on the area where the object to be measured is located.