On the benefits of correcting brightness and contrast in global digital image correlation: Monitoring cracks during curing and drying of a refractory castable

The gray level conservation is the underlying hypothesis of Digital Image Correlation (DIC). However, it may be challenging to enforce in some experimental configurations. Brightness and contrast corrections (BCCs) added registration procedure. Different types BCCs were implemented for global DIC, their benefits analyzed localized diffuse sources brightness changes. As a case study apply BCCs, refractory castable was placed inside climatic chamber, cracks generated due expansions during its curing drying. To choose best BCC this case, two sets images considered. first one allowed noise floor levels evaluated. second dealt with development crack network. significantly reduced residuals enabling small openings detected. coarse discretization effective correcting lighting changes avoided coupling measured kinematic fields other local phenomena.