** This is part of the CTSim program
** Copyright (c) 1983-2001 Kevin Rosenberg
**
-** $Id: projections.cpp,v 1.70 2001/03/24 05:28:28 kevin Exp $
+** $Id: projections.cpp,v 1.71 2001/03/28 16:53:43 kevin Exp $
**
** 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
const int Projections::s_iInterpCount = sizeof(s_aszInterpName) / sizeof(char*);
+
/* NAME
* Projections Constructor for projections matrix storage
*
double dInterpScale = (m_nDet-1) / static_cast<double>(iInterpDet-1) / SQRT2;
double dFFTScale = 1. / static_cast<double>(iInterpDet * iInterpDet);
- dFFTScale /= 2; // Not sure why this scaling is necessary
+ int iMidPoint = iInterpDet / 2;
+ double dMidPoint = static_cast<double>(iInterpDet) / 2.;
+ int iZerosAdded = iNumInterpDetWithZeros - iInterpDet;
for (unsigned int iView = 0; iView < m_nView; iView++) {
DetectorValue* detval = getDetectorArray(iView).detValues();
LinearInterpolator<DetectorValue> projInterp (detval, m_nDet);
for (unsigned int iDet = 0; iDet < iInterpDet; iDet++) {
// double dInterpPos = iInterpDet * dInterpScale;
- double dInterpPos = (m_nDet / 2.) + (iDet - iInterpDet/2.) * dInterpScale;
- pcIn[iDet].re = projInterp.interpolate (dInterpPos);
+ double dInterpPos = (m_nDet / 2.) + (iDet - dMidPoint) * dInterpScale;
+ pcIn[iDet].re = projInterp.interpolate (dInterpPos) * PI * SQRT2;
pcIn[iDet].im = 0;
}
- for (unsigned int iDet2 = iInterpDet; iDet2 < iNumInterpDetWithZeros; iDet2++)
- pcIn[iDet2].re = pcIn[iDet2].im = 0;
+ Fourier::shuffleFourierToNaturalOrder (pcIn, iInterpDet);
+ if (iZerosAdded > 0) {
+ for (unsigned int iDet1 = iMidPoint; iDet1 < iInterpDet; iDet1++)
+ pcIn[iDet1+iZerosAdded] = pcIn[iDet1];
+ for (unsigned int iDet2 = iMidPoint; iDet2 < iMidPoint + iZerosAdded; iDet2++)
+ pcIn[iDet2].re = pcIn[iDet2].im = 0;
+ }
fftw_one (plan, pcIn, NULL);
ppcDetValue[iView] = new std::complex<double> [iNumInterpDetWithZeros];
- for (unsigned int iD = 0; iD < iNumInterpDetWithZeros; iD++)
+ for (unsigned int iD = 0; iD < iNumInterpDetWithZeros; iD++) {
ppcDetValue[iView][iD] = std::complex<double> (pcIn[iD].re * dFFTScale, pcIn[iD].im * dFFTScale);
+ }
Fourier::shuffleFourierToNaturalOrder (ppcDetValue[iView], iNumInterpDetWithZeros);
}