** This is part of the CTSim program
** Copyright (c) 1983-2001 Kevin Rosenberg
**
-** $Id: projections.cpp,v 1.80 2002/06/27 03:19:23 kevin Exp $
+** $Id: projections.cpp,v 1.81 2003/03/15 10:27:30 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
******************************************************************************/
#include "ct.h"
-#include <ctime>\r
+#include <ctime>
const kuint16 Projections::m_signature = ('P'*256 + 'J');
if (m_geometry == Scanner::GEOMETRY_EQUIANGULAR || m_geometry == Scanner::GEOMETRY_EQUILINEAR)
pProj = interpolateToParallel();
- int iInterpDet = nx;
-// int iInterpDet = pProj->m_nDet;
+ int iInterpDet = static_cast<int>(static_cast<double>(sqrt(nx*nx+ny*ny)));
int iNumInterpDetWithZeros = ProcessSignal::addZeropadFactor (iInterpDet, iZeropad);
-
+ double dProjScale = iInterpDet / (pProj->viewDiameter() * 0.5);
double dZeropadRatio = static_cast<double>(iNumInterpDetWithZeros) / static_cast<double>(iInterpDet);
fftw_plan plan = fftw_create_plan (iNumInterpDetWithZeros, FFTW_FORWARD, FFTW_IN_PLACE | FFTW_ESTIMATE | FFTW_USE_WISDOM);
fftw_complex* pcIn = new fftw_complex [iNumInterpDetWithZeros];
std::complex<double>** ppcDetValue = new std::complex<double>* [pProj->m_nView];
- double dInterpScale = (pProj->m_nDet-1) / static_cast<double>(iInterpDet-1) / SQRT2;
+ //double dInterpScale = (pProj->m_nDet-1) / static_cast<double>(iInterpDet-1);
+ double dInterpScale = pProj->m_nDet / static_cast<double>(iInterpDet);
double dFFTScale = 1. / static_cast<double>(iInterpDet * iInterpDet);
int iMidPoint = iInterpDet / 2;
double dMidPoint = static_cast<double>(iInterpDet) / 2.;
int iZerosAdded = iNumInterpDetWithZeros - iInterpDet;
- // For each view, interpolate to nx length, shift to center at origin, and FFt transform
+ // For each view, interpolate, shift to center at origin, and FFT
for (int iView = 0; iView < m_nView; iView++) {
DetectorValue* detval = pProj->getDetectorArray(iView).detValues();
LinearInterpolator<DetectorValue> projInterp (detval, pProj->m_nDet);
for (int iDet = 0; iDet < iInterpDet; iDet++) {
double dInterpPos = (m_nDet / 2.) + (iDet - dMidPoint) * dInterpScale;
- pcIn[iDet].re = projInterp.interpolate (dInterpPos) * dInterpScale;
+ pcIn[iDet].re = projInterp.interpolate (dInterpPos) * dProjScale;
pcIn[iDet].im = 0;
}
Fourier::shuffleFourierToNaturalOrder (pcIn, iInterpDet);
if (iZerosAdded > 0) {
- for (int iDet1 = iMidPoint; iDet1 < iInterpDet; iDet1++)
+ for (int iDet1 = iInterpDet -1; iDet1 >= iMidPoint; iDet1--)
pcIn[iDet1+iZerosAdded] = pcIn[iDet1];
for (int iDet2 = iMidPoint; iDet2 < iMidPoint + iZerosAdded; iDet2++)
pcIn[iDet2].re = pcIn[iDet2].im = 0;
double xInc = (xMax - xMin) / nx; // size of cells
double yInc = (yMax - yMin) / ny;
+ double dDetCenter = (iNumDetWithZeros - 1) / 2.; // index refering to L=0 projection
// +1 is correct for frequency data, ndet-1 is correct for projections
- int iDetCenter = (iNumDetWithZeros - 1) / 2; // index refering to L=0 projection
- if (isEven (iNumDetWithZeros))
- iDetCenter = (iNumDetWithZeros + 1) / 2;
+ // if (isEven (iNumDetWithZeros))
+ // dDetCenter = (iNumDetWithZeros + 0) / 2;
// Calculates polar coordinates (view#, det#) for each point on phantom grid
double x = xMin + xInc / 2; // Rectang coords of center of pixel
}
ppdView[ix][iy] = (phi - m_rotStart) / m_rotInc;
- ppdDet[ix][iy] = (r / dDetInc) + iDetCenter;
+ ppdDet[ix][iy] = (r / dDetInc) + dDetCenter;
}
}
}