skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on November 7, 2020

Title: Spatial DIC Errors due to Pattern-Induced Bias and Grey Level Discretization

Abstract

Digital image correlation (DIC) is an optical metrology method widely used in experimental mechanics for full-field shape, displacement and strain measurements. The required strain resolution for engineering applications of interest mandates DIC to have a high image displacement matching accuracy, on the order of 1/100th of a pixel, which necessitates an understanding of DIC errors. In this paper, we examine two spatial bias terms that have been almost completely overlooked. They cause a persistent offset in the matching of image intensities and thus corrupt DIC results. We name them pattern-induced bias (PIB), and intensity discretization bias (IDB). We show that the PIB error occurs in the presence of an undermatched shape function and is primarily dictated by the underlying intensity pattern for a fixed displacement field and DIC settings. The IDB error is due to the quantization of the gray level intensity values in the digital camera. In this paper we demonstrate these errors and quantify their magnitudes both experimentally and with synthetic images.

Authors:
ORCiD logo [1];  [1];  [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1574475
Report Number(s):
SAND-2019-13784J
Journal ID: ISSN 0014-4851; 681363
Grant/Contract Number:  
AC04-94AL85000; NA0003525
Resource Type:
Accepted Manuscript
Journal Name:
Experimental Mechanics
Additional Journal Information:
Journal Name: Experimental Mechanics; Journal ID: ISSN 0014-4851
Publisher:
Springer
Country of Publication:
United States
Language:
English
Subject:
Digital image correlation; Pattern induced bias; Intensity discretization bias; Pattern induced errors; Uncertainty quantification

Citation Formats

Fayad, S. S., Seidl, D. T., and Reu, P. L. Spatial DIC Errors due to Pattern-Induced Bias and Grey Level Discretization. United States: N. p., 2019. Web. doi:10.1007/s11340-019-00553-9.
Fayad, S. S., Seidl, D. T., & Reu, P. L. Spatial DIC Errors due to Pattern-Induced Bias and Grey Level Discretization. United States. doi:10.1007/s11340-019-00553-9.
Fayad, S. S., Seidl, D. T., and Reu, P. L. Thu . "Spatial DIC Errors due to Pattern-Induced Bias and Grey Level Discretization". United States. doi:10.1007/s11340-019-00553-9.
@article{osti_1574475,
title = {Spatial DIC Errors due to Pattern-Induced Bias and Grey Level Discretization},
author = {Fayad, S. S. and Seidl, D. T. and Reu, P. L.},
abstractNote = {Digital image correlation (DIC) is an optical metrology method widely used in experimental mechanics for full-field shape, displacement and strain measurements. The required strain resolution for engineering applications of interest mandates DIC to have a high image displacement matching accuracy, on the order of 1/100th of a pixel, which necessitates an understanding of DIC errors. In this paper, we examine two spatial bias terms that have been almost completely overlooked. They cause a persistent offset in the matching of image intensities and thus corrupt DIC results. We name them pattern-induced bias (PIB), and intensity discretization bias (IDB). We show that the PIB error occurs in the presence of an undermatched shape function and is primarily dictated by the underlying intensity pattern for a fixed displacement field and DIC settings. The IDB error is due to the quantization of the gray level intensity values in the digital camera. In this paper we demonstrate these errors and quantify their magnitudes both experimentally and with synthetic images.},
doi = {10.1007/s11340-019-00553-9},
journal = {Experimental Mechanics},
number = ,
volume = ,
place = {United States},
year = {2019},
month = {11}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on November 7, 2020
Publisher's Version of Record

Save / Share:

Works referenced in this record:

The effect of out-of-plane motion on 2D and 3D digital image correlation measurements
journal, October 2008


Systematic errors in digital image correlation caused by intensity interpolation
journal, November 2000


The Effect of the Ill-posed Problem on Quantitative Error Assessment in Digital Image Correlation
journal, November 2017


The errors in digital image correlation due to overmatched shape functions
journal, February 2015


A Critical Comparison of Some Metrological Parameters Characterizing Local Digital Image Correlation and Grid Method
journal, April 2017


DIC Challenge: Developing Images and Guidelines for Evaluating Accuracy and Resolution of 2D Analyses
journal, December 2017


Rendering Deformed Speckle Images with a Boolean Model
journal, December 2017

  • Sur, Frédéric; Blaysat, Benoît; Grédiac, Michel
  • Journal of Mathematical Imaging and Vision, Vol. 60, Issue 5
  • DOI: 10.1007/s10851-017-0779-4

Accurate displacement measurement via a self-adaptive digital image correlation method based on a weighted ZNSSD criterion
journal, January 2014


Bias reduction in sub-pixel image registration based on the anti-symmetric feature
journal, February 2016


LOWESS: A Program for Smoothing Scatterplots by Robust Locally Weighted Regression
journal, February 1981

  • Cleveland, William S.
  • The American Statistician, Vol. 35, Issue 1
  • DOI: 10.2307/2683591