A new technique which can measure speckle phase with high accuracy is proposed. The technique continuously captures about 100 images under slow phase-shifting and then calculates phase data about each captured image. The calculated phase data are averaged along the capturing order to suppress the noise components due to air fluctuation and vibration of circumstance. Only the average, without other filtering, is not enough to suppress noise which are caused by low modulation data in specklegrams. Therefore, the average is combined with the data replacing which replaces low modulation data with high modulation data around them. The well-known median filter is also combined. With the combined method the fluctuation of phase data is extremely improved. Utility of the combined method is demonstrated through a practical deformation measurement.
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