Fig. 1.
(a) PD ratio versus true shear moduli ratio in the train set materials. The 3rd order polynomial fit (red) indicates the empirical model that was derived to convert qualitative PD ratios to quantitative shear moduli ratios. (b) Shear moduli ratios predicted by the derived empirical model versus true shear moduli ratios for test set materials. Data are plotted as median ± 0.5×interquartile range over 20 independent speckle realizations. LoE = Line of equivalency, RMSE = root mean square error, SNR = signal-to-noise ratio.