Optimized super-resolution promote accuracy for projection speckle three-dimensional digital image correlation

The camera resolution and electronic noise limit the accuracy of the projection speckle three-dimensional digital image correlation (3D-DIC) which is a non-invasive method to detect the reliability of electronic packaging structure. In this study, a measurement method of super-resolution (SR) reconstruction coupled with projection speckle DIC is proposed. The algorithm based on the maximum a posteriori model for DIC measurement systems was also optimized, and a speckle-specific bimodal prior was proposed to adapt to speckle images. By using optimized SR technology as an image pre-processing technique to enhance the resolution of captured images, the accuracy of measurements is improved. Full-field displacement measurement experiments show that, with suitable magnification and speckle size, the use of SR technology reduces the range of displacement errors from 8 & mu;m to 2 & mu;m. Experiments on step block topography measurements show that the use of SR technology reduces the error between DIC measurements and Moire interferometry from 5 & mu;m to within 2 & mu;m. Therefore, SR technology can be effectively paired with projection speckle DIC measurements to adapt to various measurement scenarios in the field of electronic packaging reliability testing.

Automated summary

In this study, a super-resolution (SR) reconstruction method coupled with projection speckle DIC was proposed to improve the accuracy of detecting the reliability of electronic packaging structure. By optimizing the algorithm based on the maximum a posteriori model for DIC measurement systems and introducing a speckle-specific bimodal prior, the accuracy of measurements was improved. Experimental results showed that the use of SR technology reduced displacement errors from 8 μm to 2 μm and reduced the error between DIC measurements and Moire interferometry from 5 μm to within 2 μm. Therefore, SR technology can effectively enhance projection speckle DIC measurements in electronic packaging reliability testing.