Cross-Correlation and Differential Technique Combination to Determine Displacement Fields

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Sousa, AMR (Author) Other; Xavier, J (Author) Other; Mário Vaz (Author) FEUP; Morais, JJL (Author) Other; Filipe, VMJ (Author) Other

Journal

Title: Strain

Vol. 47

Pages: 87-98

ISSN: 0039-2103

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 32 Citations

Scopus - 35 Citations

Other information

Authenticus ID: P-002-HWG

DOI: 10.1111/j.1475-1305.2010.00740.x

Abstract (EN): This study presents a method to measure the displacement fields on the surface of planar objects with sub-pixel resolution, by combining image correlation with a differential technique. First, a coarse approximation of the pixel level displacement is obtained by cross-correlation (CC). Two consecutive images, taken before and after the application of a given deformation, are recursively split in sub-images, and the CC coefficient is used as the similarity measure. Secondly, a fine approximation is performed to assess the sub-pixel displacements by means of an optical flow method based on a differential technique. To validate the effectiveness and robustness of the proposed method, several numerical tests were carried out on computer-generated images. Moreover, real images from a static test were also processed for estimating the displacement resolution. The results were compared with those obtained by a commercial digital image correlation code. Both methods showed similar and reliable results according to the proposed tests.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12