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/*****************************************************************************
** FILE IDENTIFICATION
**
** Name: fourier.cpp
** Purpose: Fourier transform functions
** Programmer: Kevin Rosenberg
** Date Started: Dec 2000
**
** This is part of the CTSim program
** Copyright (c) 1983-2009 Kevin Rosenberg
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License (version 2) as
** published by the Free Software Foundation.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
******************************************************************************/
#include "ct.h"
void
Fourier::shuffleFourierToNaturalOrder (ImageFile& im)
{
ImageFileArray vReal = im.getArray();
ImageFileArray vImag = im.getImaginaryArray();
unsigned int ix, iy;
unsigned int nx = im.nx();
unsigned int ny = im.ny();
// shuffle each column
for (ix = 0; ix < nx; ix++) {
Fourier::shuffleFourierToNaturalOrder (vReal[ix], ny);
if (im.isComplex())
Fourier::shuffleFourierToNaturalOrder (vImag[ix], ny);
}
// shuffle each row
float* pRow = new float [nx];
for (iy = 0; iy < ny; iy++) {
for (ix = 0; ix < nx; ix++)
pRow[ix] = vReal[ix][iy];
Fourier::shuffleFourierToNaturalOrder (pRow, nx);
for (ix = 0; ix < nx; ix++)
vReal[ix][iy] = pRow[ix];
if (im.isComplex()) {
for (ix = 0; ix < nx; ix++)
pRow[ix] = vImag[ix][iy];
Fourier::shuffleFourierToNaturalOrder (pRow, nx);
for (ix = 0; ix < nx; ix++)
vImag[ix][iy] = pRow[ix];
}
}
delete pRow;
}
void
Fourier::shuffleNaturalToFourierOrder (ImageFile& im)
{
ImageFileArray vReal = im.getArray();
ImageFileArray vImag = im.getImaginaryArray();
unsigned int ix, iy;
unsigned int nx = im.nx();
unsigned int ny = im.ny();
// shuffle each x column
for (ix = 0; ix < nx; ix++) {
Fourier::shuffleNaturalToFourierOrder (vReal[ix], ny);
if (im.isComplex())
Fourier::shuffleNaturalToFourierOrder (vImag[ix], ny);
}
// shuffle each y row
float* pRow = new float [nx];
for (iy = 0; iy < ny; iy++) {
for (ix = 0; ix < nx; ix++)
pRow[ix] = vReal[ix][iy];
Fourier::shuffleNaturalToFourierOrder (pRow, nx);
for (ix = 0; ix < nx; ix++)
vReal[ix][iy] = pRow[ix];
if (im.isComplex()) {
for (ix = 0; ix < nx; ix++)
pRow[ix] = vImag[ix][iy];
Fourier::shuffleNaturalToFourierOrder (pRow, nx);
for (ix = 0; ix < nx; ix++)
vImag[ix][iy] = pRow[ix];
}
}
delete [] pRow;
}
#ifdef HAVE_FFTW
void Fourier::shuffleNaturalToFourierOrder (fftw_complex* pVector, const int n)
{
fftw_complex* pTemp = static_cast<fftw_complex*>(fftw_malloc(sizeof(fftw_complex) * n));
int i;
if (isOdd(n)) { // Odd
int iHalfN = (n - 1) / 2;
pTemp[0][0] = pVector[iHalfN][0];
pTemp[0][1] = pVector[iHalfN][1];
for (i = 0; i < iHalfN; i++) {
pTemp[i + 1][0] = pVector[i + 1 + iHalfN][0];
pTemp[i + 1][1] = pVector[i + 1 + iHalfN][1];
}
for (i = 0; i < iHalfN; i++) {
pTemp[i + iHalfN + 1][0] = pVector[i][0];
pTemp[i + iHalfN + 1][1] = pVector[i][1];
}
} else { // Even
int iHalfN = n / 2;
pTemp[0][0] = pVector[iHalfN][0];
pTemp[0][1] = pVector[iHalfN][1];
for (i = 0; i < iHalfN - 1; i++) {
pTemp[i + 1][0] = pVector[i + iHalfN + 1][0];
pTemp[i + 1][1] = pVector[i + iHalfN + 1][1];
}
for (i = 0; i < iHalfN; i++) {
pTemp[i + iHalfN][0] = pVector[i][0];
pTemp[i + iHalfN][1] = pVector[i][1];
}
}
for (i = 0; i < n; i++) {
pVector[i][0] = pTemp[i][0];
pVector[i][1] = pTemp[i][1];
}
fftw_free(pTemp);
}
void Fourier::shuffleFourierToNaturalOrder (fftw_complex* pVector, const int n)
{
fftw_complex* pTemp = static_cast<fftw_complex*>(fftw_malloc(sizeof(fftw_complex) * n));
int i;
if (isOdd(n)) { // Odd
int iHalfN = (n - 1) / 2;
pTemp[iHalfN][0] = pVector[0][0];
pTemp[iHalfN][1] = pVector[0][1];
for (i = 0; i < iHalfN; i++) {
pTemp[i + 1 + iHalfN][0] = pVector[i + 1][0];
pTemp[i + 1 + iHalfN][1] = pVector[i + 1][1];
}
for (i = 0; i < iHalfN; i++) {
pTemp[i][0] = pVector[i + iHalfN + 1][0];
pTemp[i][1] = pVector[i + iHalfN + 1][1];
}
} else { // Even
int iHalfN = n / 2;
pTemp[iHalfN][0] = pVector[0][0];
pTemp[iHalfN][1] = pVector[0][1];
for (i = 0; i < iHalfN; i++) {
pTemp[i][0] = pVector[i + iHalfN][0];
pTemp[i][1] = pVector[i + iHalfN][1];
}
for (i = 0; i < iHalfN - 1; i++) {
pTemp[i + iHalfN + 1][0] = pVector[i+1][0];
pTemp[i + iHalfN + 1][1] = pVector[i+1][1];
}
}
for (i = 0; i < n; i++) {
pVector[i][0] = pTemp[i][0];
pVector[i][1] = pTemp[i][1];
}
fftw_free(pTemp);
}
#endif
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