Tay, C.J.Fu, Y.MECHANICAL ENGINEERING2014-06-172014-06-172005-11-01Tay, C.J., Fu, Y. (2005-11-01). Determination of curvature and twist by digital shearography and wavelet transforms. Optics Letters 30 (21) : 2873-2875. ScholarBank@NUS Repository. https://doi.org/10.1364/OL.30.00287301469592https://scholarbank.nus.edu.sg/handle/10635/59879A new technique based on digital shearography for determining the transient curvature and twist of a continuously deforming object from a series of speckle patterns is presented. The intensity variation of each pixel is analyzed along the time axis by using a complex Morlet wavelet transform. The absolute sign of the phase variation is determined by introduction of a temporal carrier when the speckle patterns are captured by a high-speed camera. A high-quality spatial distribution of the deflection derivative is extracted at any instant without the need for temporal or spatial phase unwrapping. The continuous Haar wavelet transform is subsequently processed as a differentiation operator to reconstruct the instantaneous curvature and twist of a continuously deforming object. © 2005 Optical Society of America.Article000232786800013