Frequency-based image analysis of random patterns: an alternative way to classical stereocorrelation [article]

Jérôme Molimard (IFRESIS-ENSMSE, CIS-ENSMSE, STBio-ENSMSE, LGF-ENSMSE), Gaetan Boyer, Hassan Zahouani
2013 arXiv   pre-print
The paper presents an alternative way to classical stereocorrelation. First, 2D image processing of random patterns is described. Sub-pixel displacements are determined using phase analysis. Then distortion evaluation is presented. The distortion is identified without any assumption on the lens model because of the use of a grid technique approach. Last, shape measurement and shape variation is caught by fringe projection. Analysis is based on two pin-hole assumptions for the video-projector
more » ... the camera. Then, fringe projection is coupled to in-plane displacement to give rise to 3D measurement set-up. Metrological characterization shows a resolution comparable to classical (stereo) correlation technique (1/100th pixel). Spatial resolution seems to be an advantage of the method, because of the use of temporal phase stepping (shape measurement, 1 pixel) and windowed Fourier transform (in plane displacements measurement, 9 pixels). Two examples are given. First one is the study of skin properties; second one is a study on leather fabric. In both cases, results are convincing, and have been exploited to give mechanical interpretation.
arXiv:1311.3864v1 fatcat:tovlwwk4jnh4fldjt3udc77slu