iconebeam

Tomographic backprojection for cone beam geometry.

This is a simple implementation of the Feldkamp-Kress-Davis (also referred to as FDK) algorithm for the reconstruction (i.e. filtered back projection) of slices from projections taken with cone beam geometry (i.e. micro-focus X ray sources).

For this demonstration we reconstruct only the central slice (z=0) of the projection that is we use the FDK as a code for the back projection of acquisitions with fan beam geometry. This allows us to exploit the matlab phantom routine to produce a synthetic projection.

For practical applications on has to write is own routine for reading the planar radiograph according to the suitable files format and correct these radiograph for the dark filed images (image registered by the detector with x ray off) and the flat filed image (x ray on and no object). Also the normalized radiograph has to the log processed and transformed into projection.

Our submission is meant to be a helpful outline for the development of a more optimized code given that Matlab offers only iradon (for parallel beams as one produced at the synchrotron beam lines) and ifanbeam routines.

The code reconstructs a volume (rather than single slices as iradon) thus an accurate evaluation of the memory necessary based on size of the planar projections is desirable.

Acknowledgement :
http://www.msri.org/publications/books/Book47/faridani/
basic FDK code
author: Faridani