Camera System Resolution and its Influence on Digital Image Correlation

被引：72
作者：
Reu, P. L. [1 ]
Sweatt, W. [1 ]
Miller, T. [1 ]
Fleming, D. [1 ]
机构：
[1] Sandia Natl Labs, Albuquerque, NM 87185 USA
来源：
EXPERIMENTAL MECHANICS | 2015年 / 55卷 / 01期
基金：
美国能源部;
关键词：
Digital image correlation; Uncertainty quantification; Optical measurements; Full-field measurement; Lens resolution; INTENSITY PATTERN NOISE; ERROR ASSESSMENT; STRAIN;
D O I：
10.1007/s11340-014-9886-y
中图分类号：
T [工业技术];
学科分类号：
08 ;
摘要：
Digital image correlation (DIC) uses images from a camera and lens system to make quantitative measurements of the shape, displacement, and strain of test objects. This increasingly popular method has had little research on the influence of the imaging system resolution on the DIC results. This paper investigates the entire imaging system and studies how both the camera and lens resolution influence the DIC results as a function of the system Modulation Transfer Function (MTF). It will show that when making spatial resolution decisions (including speckle size) the resolution limiting component should be considered. A consequence of the loss of spatial resolution is that the DIC uncertainties will be increased. This is demonstrated using both synthetic and experimental images with varying resolution. The loss of image resolution and DIC accuracy can be compensated for by increasing the subset size, or better, by increasing the speckle size. The speckle-size and spatial resolution are now a function of the lens resolution rather than the more typical assumption of the pixel size. The paper will demonstrate the tradeoffs associated with limited lens resolution.
引用
收藏
页码：9 / 25
页数：17
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