Shape measurement by grating projection and whole-space tabulation method

The authors previously proposed a shape measurement method using pixel-by-pixel calibration tables produced with multiple reference planes. In this method, all the relationships between the phase of the projected grating and the spatial coordinates can be obtained for each pixel. This method is called ‘whole-space tabulation method’. This method excludes a lens distortion and intensity errors of the projected grating in measurement results theoretically. Tabulation makes a high-speed and accurate shape measurement possible. The principle of the shape measurement using the whole-space tabulation method and some results of shape measurements using this method are shown.