2018
Comment:

← Revision 16 as of 20130701 13:12:58 ⇥
2018
converted to 1.6 markup

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["recons3d_sirt"]  [[recons3d_sirt]] 
Name
recons3d_wbp  calculate 3D reconstruction from a set of projections using weighted backprojection method (general or exact filter) or perform a simple backprojection
Usage
vol = recons3d_wbp(stack, list_proj, method [, symmetry, const])
Input
 stack
name of the stack file or an incore stack containing projection data, projections have to be squares, i.e., nx=ny.
 list_proj
 list of projections to be included in the reconstruction.
 symmetry
 pointgroup symmetry to be enforced, each projection will enter the reconstruction in all symmetryrelated directions. The possibilities are
 "cn"
 "dn"
 "i"
 "c1" (no symmetry) is the default.
 method
method used in WBP reconstruction, could either be general, exact, or empty string " ". The last indicates simple backprojection.
 const
for general, it should correspond to the SNR of the reconstruction, the default is 1.0E4; for exact, it should be the diameter of the structure in pixels.
Output
 vol
 the 3D reconstructed volume
Method
 general
 the weighting function is constructed as a sum of Gaussian function of distances between projection pixels in Fourier space, as described in: M. Radermacher, Weighted BackProjection Methods. (p.102) In: Electron Tomography. Ed.: J. Frank, 1992.
 exact
 the weighting function is constructed as a sum of "overlaps" between Fourier transforms of projections, as described in: G. Harauz and M. van Heel, Exact filters for general geometry three dimensional reconstruction.Optik 73 (1986) 146156. The smaller the diameter, the stronger the lowpass filtration effect on the reconstructed object.
 " "
 the projections are backprojected, no weighting applied
Author / Maintainer
Pawel A. Penczek
Keywords
 category 1
 INVERSION
 category 2
 FOURIER
Files
reconstruction.py
See also
Maturity
 alpha
Bugs
None. It is perfect.