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BP WY - Back Projection - weighted, Y

(9/17/94)

PURPOSE

This is the first step of the weighted back projection for a tilt series with equal angular increment (not statistical). A series of projections is weighted by R in Fourier space. The direction (X or Y <> wx or wy) depends on the tilting and reconstruction geometry (see 'BP XY', the simple back projection used in the second step of the reconstruction.

SEE ALSO

BP 3 [Back Projection - 3D, iterative]
BP 3D [Back Projection - 3D, using Euler angles, ||]
BP 3E [Back Projection - 3D, using Euler angles]
BP CTF [Back Projection - 3D, CTF correction, ||]
BP GW [Back Projection - weighted, arbitrary geometry]
BP GW3 [Back Projection - weighted, arbitrary geometry, 3 angles]
BP MEM2 [Back Projection - 2D maximum entropy method]
BP R2 [Back Projection - 2D, R**2 weighting of the image series]
BP RP [Back Projection - 3D, iterative, with constraints, ||]
BP S2 [Back Projection - 2D, single tilt iterative, with constraints]
BP W2 [Back Projection - 2D, filtered weighted]
BP WX [Back Projection - weighted, X]
BP WY [Back Projection - weighted, Y]
BP XY [Back Projection - simple for single axis & conical tilting]

USAGE

.OPERATION: BP WY

.FIRST FILE: PRO001
[Enter the name of the first projection.]

.LAST FILE: PRO020
[Enter the name of the last projection.]

.OUTPUT FILE TEMPLAT: WEIGHT***
[Enter template for output file names]

.START AT RADIUS 0 OR 1: 0
[For a single axis tilt series the average per projection line should be preserved. thus answer 1. otherwise for true * weighting answer 0]

NOTES

  1. The projections must have power-of-2 dimensions. Maximum size of projections is currently 128x128.

  2. The file series need not be contiguous; gaps in the file numbers are allowed.

SUBROUTINES

WEIGHTC, WEIGHTF, WEIFU, WEIFU3, FOUR2

CALLER

VTIL2

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