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RM FT - Fourier transform Radon transform

((2d and 3d, mixed radix))

PURPOSE

Computes Fourier transform of a 2d or 3d Radon transform. Applies Fourier filters.

USAGE

.OPERATION: RM FT

.RADON INPUT FILE: RAD001
[Enter name of treal space Radon transform.]

.(P)AD INPUT FILE: P
[Answer P if you want to pad the input file.]

If P was answered:
.PADDING DIMENSION: 140

ENTER * IF NO REAL SPACE OUTPUT DESIRED:
.RADON OUTPUT FILE: RADOUT001
[Enter a file name if you desire a back transformed output file, e.g. for Fourier filtration.]

.RADON FOURIER OUTPUT FILE: RADFOUR001
[Enter name of Fourier output file. Enter * if no such file is desired.]

.FOURIER FILTER Y/N: Y
[Enter Y if you want to Fourier filter the transform.]

if "Y" was answered:

.# OF FILTRATIONS 1/2: 2
[Enter 2 if you want to combine two filters, 1 if only one filter is to be used.]

.(A)DDITIVE (=DEF),(M)ULTIPLICATIVE: M
[Combine the chosen filters either additive or multiplicative. For a band pass filter M is the ususal option.]

.(1)L.P./(2)H.P./(3)G.L.P./(4)G.H.P./(5)F.L.P./(6)F.H.P.,(7) R*: 5
[Enter desired filter. Similar to SPIDER opreation FF. 1: cutoff low pass filter, 2: cutoff high pass filter 3: Gaussian low pass filter, 4: Gaussian high pass filter. 5: Fermi low-pass filter, 6: Fermi high pass filter. 7: Multiplication with r* (the Fourier radius). 8: Multiplication with sqrt(r*).

.FILTER RADIUS: 0.123
[Enter filter radius. also otion 7 currently asks for a radius, but the value is ignored.]

for Fermi filter:

.TEMPERATURE(0=CUTOFF): 0.03
[Enter temperature factor for fermi filter.]

[End of question concerning filtrations.]

.(A)MPLITUDE NORMALISATION FOR PHASE CORRELATION: A
[Answer A if the the Fourier coefficients should be normalized by their value. A Wiener style filter is applied. If NF is the n new Fourier coefficient and OF is the old value the normalization formula is: NF = OF / (|OF| + epsilon).

if A was answered:

.EPSILON (0 TO 1): 0.001
[Enter value of epsilon for amplitude normailzatioon.]

.(S)IGMA NORMALIZATION: N
[Enter S if each line in the Fourier transform is to be normailzed by its own sigma. Otherwise enter N. Sigma for each line is stored with the Fourier transform for later usage in this case.]

NOTES

  1. Output has x-dimension of NSAM+2

  2. Developed by: M.Radermacher

  3. Not Distributed!

SUBROUTINES

FOURADCALL, FOURAD, MRFOUR1

CALLER

UTIL5

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