Elimination of interpolation error in digital volume correlation: introducing Shift-DVC

• Proposal of the Shift-DVC strategy to eliminate the systematic error caused by intensity interpolation. • Simple implementation in classical DVC codes to reduce the intensity interpolation error by a factor of up to 4. • Significant decrease in computation time required for convergence. This study addresses one of the major factors affecting the metrological performance of Digital Volume Correlation (DVC), namely the systematic error caused by intensity interpolation, which is characterized by an S-shaped bias error. While random error can be reduced by improving image quality, systematic error cannot be avoided. To overcome this issue, a strategy called Shift-DVC is proposed to eliminate this systematic error in DVC. In classical DVC techniques, points of interest (POIs) are located at integer positions. In contrast, the proposed Shift-DVC strategy introduces specific offsets to the conventional positions, causing the POIs to be located at non-integer positions where the S-shaped bias error is reduced. This method, which is simple to implement in classical DVC code, reduces the intensity interpolation error by a factor of up to four and significantly decreases the computation time required for convergence.