Equivalence of digital image correlation criteria for pattern matching

Area of Science:

• * Mechanical Engineering
• * Optical Measurement Techniques
• * Materials Science

Background:

• * Digital Image Correlation (DIC) relies on correlation criteria to measure displacements.
• * Various DIC correlation criteria exist, but their relationships are underexplored.
• * Robust criteria like ZNCC, ZNSSD, and PSSD(ab) are vital for accurate intensity-invariant measurements.

Purpose of the Study:

• * To provide a comprehensive overview of DIC correlation criteria.
• * To analyze the relationships between ZNCC, ZNSSD, and PSSD(ab) criteria.
• * To demonstrate the theoretical and practical equivalence of these three DIC criteria.

Main Methods:

• * Literature review of existing DIC correlation criteria.
• * Theoretical analysis of transversal relationships between ZNCC, ZNSSD, and PSSD(ab).
• * Numerical simulations and experimental validation of criterion equivalence.

Main Results:

• * Established transversal relationships among ZNCC, ZNSSD, and PSSD(ab).
• * Demonstrated the theoretical equivalence of the three correlation criteria.
• * Validated the equivalence through numerical simulations and experimental data.

Conclusions:

• * The ZNCC, ZNSSD, and PSSD(ab) criteria are theoretically equivalent for DIC.
• * This equivalence unifies pattern matching approaches in DIC.
• * The findings simplify the selection and application of robust DIC correlation criteria.