Strain contouring using Gabor filters: principle and algorithm

Moire interferometry is a powerful technique for high sensitivity in-plane deformation contouring. However, from an engineering viewpoint, the derivatives of displacement, i.e., strain, are the desired parameter. Thus there is a need to differentiate the displacement field. Optical and digital methods have been proposed for this differentiation. Optical methods provide contours that still need to be quantified, while digital methods suffer from drawbacks inherent in the digital differentiation process. We describe a novel approach of strain segmentation for the moire pattern using a multichannel Gabor filter. Appropriate filter design allows for user-specific segmentation, which is essentially in engineering design and analysis. (C) 2002 Society of Photo-Optical Instrumentation Engineers.