Digital Image Correlation (DIC) is an optical technique that compares multiple images of a tested specimen’s surface to generate full-field strain and displacement maps. It creates pictures that can be used to visualize strain and displacement over the full two-dimensional surface of the test specimen. The benefits of DIC include measuring strain without requiring physical contact, viewing full-field data (like thousands of tiny extensometers), and not needing to know where to place the strain gauge/extensometer before a test starts.

The following presentation gives an introduction to this optical technique:

Introduction to Digital Image Correlation (DIC)