Projection-angle-dependent image intensifier distortion correction in high-speed tomography

The geometric distortion pattern induced by electron deflection in x-ray image intensifiers is strongly influenced by the surrounding magnetic field. Therefore, variations in the magnetic field as sensed by the image intensifier causes the distortion pattern to alter accordingly, as is the case in C-arm imaging. In this work, we present a method to correct the image intensifier distortion, based on digital image correlation, and we show how this method can be efficiently used to correct for the time-varying distortion induced by an inhomogeneous distribution of ferromagnetic components in the sample rotation stage. Our experiments show that any projection recorded under an arbitrary angle can be corrected with a mean residual error below 0.48 pixels, using only three projection images of a custom reference mask sampled with a 120° angular interval to estimate the distortion behavior throughout a full rotation of the stage. As the method relies on widely available DIC software, it is very accessible and easy to use.

Publication year:2020

Keywords:P3 Proceeding

Accessibility:Open