English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The pseudo-polar Fourier transform is a specialized non-equally spacedFourier transform, which evaluates the Fourier transform on a near-polar grid,known as the pseudo-polar grid. The advantage of the pseudo-polar grid overother non-uniform sampling geometries is that the transformation, which samplesthe Fourier transform on the pseudo-polar grid, can be inverted using a fastand stable algorithm. For other sampling geometries, even if the non-equallyspaced Fourier transform can be inverted, the only known algorithms areiterative. The convergence speed of these algorithms as well as their accuracyare difficult to control, as they depend both on the sampling geometry as wellas on the unknown reconstructed object. In this paper, we present a directinversion algorithm for the three-dimensional pseudo-polar Fourier transform.The algorithm is based only on one-dimensional resampling operations, and isshown to be significantly faster than existing iterative inversion algorithms.

Direct Inversion of the 3D Pseudo-polar Fourier Transform