Sampling strategies in multiple-image radiography

Multiple-Image Radiography (MIR) is an analyzer-based phase-sensitive x-ray imaging method, which is a potential alternative to conventional radiography. MIR simultaneously generates three planar images containing information about scattering, refraction and absorption properties of the object. These parametric images are acquired by sampling the angular intensity profile of the beam passing through the object at different positions of the analyzer crystal. Like many of the modern imaging techniques, MIR is a computing imaging method and the noise in MIR, in addition to the imaging conditions, depends also on the estimation of the parameters. In this work, we use Cramer-Rao lower bound to quantify the noise in MIR estimated images and investigate the effect of different sampling strategies at the analyzer on this bound. We also evaluate the performance of an estimator with respect to this bound.