Deformation Measurement Of Object Based On Speckle Photography

This paper presents a method of deformation measurement combining speckle photography and digital phase-shifting technique in order to realize three dimensional deformation non-contact measurement. CCD and EALCD are used to record and reconstruct in optical system, which ensure the digitalization and real time measurement. Digital image processing is used in the four steps phase-shifting, which replaces complex phase shift devices such as PZT(Piezoelectric Translator) and phase controller. Phase-unwrapping method is used to realize3D deformation phase testing. The measurement system is effectively simplified. In this way3D phase distribution which includes the deformation information is successfully achieved. Then, the image processing is used to reduce the influence of the high noise and the inhomogeneous grey of the speckle interferogram.The research indicates that this method simplifies the traditional speckle photography measurement system and it can be simple to operate, rapid to get a high precision measurement result which can reach up to λ/10, and it has a great use value.