Wide measurement range deformation measurement method and its program

摘要

To solve the problem of reproductivity and efficiency in a situation where two grids with different pitches have to be prepared and respectively photographed twice before/after deformation when phase connection is to be applied to a conventional monochrome grid.SOLUTION: One color grid is generated where red and blue grids with different pitches are plotted. Then, two gray scale images are obtained by separating color images respectively photographed once before/after deformation into a R (red) component and a B (blue) component with the use of a color digital camera. A phase difference is calculated from phase distributions before/after deformation of an expanded pitch obtained by performing phase connection of phase distributions having moire patterns with different pitches acquired from the two gray scale images. Then, a long measurement range displacement distribution is obtained.SELECTED DRAWING: Figure 3