view article

Figure 3
Demonstration of the projection pair approach. Using data set tomo_00030 from TomoBank (De Carlo et al., 2018BB8) (a), ten sets of θ-sums were obtained from projection pairs that were each separated by 180° in the sinogram (b). The corresponding θ-sums for each projection pair are shown in (c), with both the projection center as recorded in the data set and the recovered rotation center shown. Because an offset from centrosymmetry leads to a phase ramp in Fourier space, Fourier transforms of each of these θ-sums shown in (d) all show the same phase ramp at the first spatial frequency index (that is, the lowest spatial frequency in the Fourier transform), with higher spatial frequencies then reflecting variations due to what exact features are present in the projection pair. The correct rotation center is recovered from the phase of the first spatial frequency index.

Journal logoJOURNAL OF
ISSN: 1600-5775
Follow J. Synchrotron Rad.
Sign up for e-alerts
Follow J. Synchrotron Rad. on Twitter
Follow us on facebook
Sign up for RSS feeds