BPD 3F - Back Projection - 3D, Interpolated in Fourier space ||*

PURPOSE

Calculates a 3D reconstruction by back-projecting the input projections using interpolation in Fourier space. THIS IS IMPROVED VERSION OF: 'BP 3F' allowing more stack usage.

SEE ALSO

BP 3F	[Back Projection - 3D, interpolated, in Fourier space ||*]
BPD 32F	[Back Projection - 3D, Sampled, Interpolated in Fourier space ||*]
BP CG	[Back Projection - 3D, conjugate gradients, ||*]
BP R2	[Back Projection - 2D, weighting of image series ||]
BP RP	[Back Projection - 3D, iterative, with constraints, ||*]
BP S2	[Back Projection - 2D, single tilt iterative, constrained ||]
RB 3F	[Rotate, Shift, Back Projection in Fourier space |]

USAGE

.OPERATION: BPD 3F

.TEMPLATE FOR IMAGE FILES (E.G. STK@****): PROJ***
[Enter a template for input image files to be back projected. This template can alternatively refer to a series of single images (e.g. img***), or to a series of stacked images (e.g stack3@***), or to a whole stack of images ending in '@' (e.g. stk@). Templates containing an asterisk will have the astericks substituted with a number for the file. (The MPI version can not use a selection file for image numbers).]

If the template contains an asterisk the following question will appear:

.ENTER FILE NUMBERS OR SELECTION DOC. FILE NAME: 1-700 OR IMAGE_SEL
[Enter projection file numbers or the name of the document file containing projection file numbers in the first column.]

.ANGLES DOC FILE: ANGLES27
[Enter the name of the document file containing Eulerian angles for the projections used (psi, theta, phi).]

.SYMMETRIES DOC FILE: symmetries
[Enter the name of the document file containing Eulerian angles defining symmetries (psi, theta, phi). The angles should be such that when used in operation 'RT 3D' transform the volume into itself. The identity operation (angles 0,0,0) MUST be included.
The symmetries are enforced in two steps: projections related by the symmetry operations are added in Fourier space to the volume; in order to reduce the residual artifacts, additional real-space symmetrization is applied.
If there are no symmetries, enter symbol "*".]

.RECONSTRUCTED VOLUME FILE: VOLUME001
[Name for the output volume calculated using all input projections specified in the selection document file.]

NOTES

1. 5x5x5 Keiser-Bessel interpolation scheme is used.

2. The projections do not have to have power-of-2 dimensions.

3. This operation parallelized for use with MPI.

4. Implemented by Paul Penczek and ArDean Leith.

SUBROUTINES

WIW32D

CALLER

VTIL2