2018 Volume 18 Issue 1 Pages 10-17
We had reported a 3D-shape measurement technique of a rough surface using speckle interferograms captured under random phase shift. Amounts of the phase shifts between captured interferograms are calculated both through Max & Min light intensities searchings at two different pixels along frames and twin normalizations of their intensity changes. The calculated phase shifts are used to extract phase distribution of a speckle interferogram. After capturing 280 specklegrams which consist of 40 specklegrams at wavelengths of 778.19 nm, 778.20 nm, 778.24 nm 778.35 nm, 778.61 nm, 779.14 nm and 780.09 nm, phase distributions are extracted regarding the first captured interferogram in each wavelength. The ratios of phase change against wavelength change are then extracted at all the pixels, and 3D shape is calculated from the extracted ratios. This 3D-shape measurement technique is now applied to an iron head of electric-solder whose temperature is rising from room temperature, RT, to 392 degree C. At the first trial, the obtained shape data have involved intense error except RT. Then we introduce some new data processing, and then analyze origins of remaining errors. Finally, effective data processing are found which can measure the 3D shape of the head at from RT to 390 degree C.
