Reliability of the image formation in the phase-contrast speckle correlation imaging technique

An investigation of the sensitivity and precision of the image formation in the phase-contrast speckle correlation imaging technique has been performed using both simulations and experiments. It was concluded that the imaging f-number controls the sensitivity and the measured phase gradient range of the measurement but does not directly influence its precision. Instead, the random error in correlation value, and as a consequence the refraction strength of the object under study, drops off as 1/<i>N</i>, where <i>N</i> is the number of image pairs recorded, while following a non-linear relation as a function of correlation value. With these findings, it is possible to choose experimental parameters that optimize both sensitivity and precision for phase imaging using the phase-contrast speckle correlation technique.