The grid method is an alternative to Digital Image Correlation (DIC) that uses a regular marking (a grid) as opposed to a random pattern. This enables the use of spatial phase-shifting algorithms to extract displacement fields. As a consequence, the spatial resolution is superior to DIC (typically, one independent displacement data point for a 5×5 pixel subset) for roughly the same displacement resolution.
Example of a grid
- A recent and valuable review paper on the grid method:
Grédiac M., Sur F., Blaysat B., The Grid Method for in-plane displacement and strain measurement: a review and analysis, Strain, vol. 52, n° 3, pp. 205-243, 2016.
- A GUI to process grid images can be found here.
- Matlab grid processing tools can be found here.