Snapshot compressive imaging based digital image correlation: temporally super-resolved full-resolution deformation...

Area of Science:

• Optical Measurement
• Materials Science
• Computational Imaging

Background:

• Digital Image Correlation (DIC) systems face limitations in achieving both high spatial and temporal resolution for deformation measurements due to throughput constraints.
• Snapshot Compressive Imaging (SCI) offers a potential solution for high-speed data acquisition in computational imaging.

Purpose of the Study:

• To develop and validate an integrated Snapshot Compressive Imaging-Digital Image Correlation (SCI-DIC) system for high-speed, high-resolution deformation measurement.
• To introduce a novel Speckle-pattern Decompress SCI (Sp-DeSCI) algorithm tailored for accurate reconstruction of speckle sequences.

Main Methods:

• An SCI-DIC system was established to encode dynamic speckle patterns into a single snapshot.
• A Sp-DeSCI algorithm was developed, incorporating normalized sum squared difference, speckle-adaptive patch search, and adaptive group aggregation for precise reconstruction.
• The system and algorithm were validated through extensive simulations and a four-point bending experiment.

Main Results:

• The Sp-DeSCI algorithm successfully reconstructed speckle sequences with reduced deviations compared to existing DeSCI methods.
• The proposed SCI-DIC system demonstrated superior displacement accuracy.
• Both simulation and real-world experiments confirmed the effectiveness of the Sp-DeSCI algorithm.

Conclusions:

• The SCI-DIC system, powered by the Sp-DeSCI algorithm, enables temporally super-resolved deformation measurement at full spatial resolution.
• This integrated approach has the potential to surpass conventional high-speed DIC systems in real-world applications.