** This is part of the CTSim program
** Copyright (c) 1983-2001 Kevin Rosenberg
**
-** $Id: backprojectors.cpp,v 1.28 2001/02/23 02:06:01 kevin Exp $
+** $Id: backprojectors.cpp,v 1.30 2001/03/07 19:02:44 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
yInc = (yMax - yMin) / ny;
m_dFocalLength = proj.focalLength();
+ m_dSourceDetectorLength = proj.sourceDetectorLength();
}
Backproject::~Backproject ()
double frac = p - pFloor; // fraction distance from det
if (iDetPos >= 0 && iDetPos < nDet - 1)
v[ix][iy] += rotScale * ((1-frac) * filteredProj[iDetPos] + frac * filteredProj[iDetPos+1]);
- } else if (interpType = Backprojector::INTERP_CUBIC) {
+ } else if (interpType == Backprojector::INTERP_CUBIC) {
double p = iDetCenter + (L / detInc); // position along detector
if (p >= 0 && p < nDet)
v[ix][iy] += rotScale * pCubicInterp->interpolate (p);
double frac = dPos - dPosFloor; // fraction distance from det
if (iDetPos >= 0 && iDetPos < nDet - 1)
pImCol[iy] += ((1-frac) * filteredProj[iDetPos] + frac * filteredProj[iDetPos+1]);
- } else if (interpType = Backprojector::INTERP_CUBIC) {
+ } else if (interpType == Backprojector::INTERP_CUBIC) {
double p = iDetCenter + (L / detInc); // position along detector
if (p >= 0 && p < nDet)
pImCol[iy] += pCubicInterp->interpolate (p);
double frac = curDetPos - detPosFloor; // fraction distance from det
if (iDetPos > 0 && iDetPos < nDet - 1)
*pImCol++ += filteredProj[iDetPos] + (frac * (filteredProj[iDetPos+1] - filteredProj[iDetPos]));
- } else if (interpType = Backprojector::INTERP_CUBIC) {
+ } else if (interpType == Backprojector::INTERP_CUBIC) {
double p = iDetCenter + curDetPos; // position along detector
if (p >= 0 && p < nDet)
*pImCol++ += pCubicInterp->interpolate (p);
if (iDetPos >= 0 && iDetPos <= iLastDet)
*pImCol++ += filteredProj[iDetPos] + (detRemainder * deltaFilteredProj[iDetPos]);
} // end for iy
- } else if (interpType = Backprojector::INTERP_CUBIC) {
+ } else if (interpType == Backprojector::INTERP_CUBIC) {
for (int iy = 0; iy < ny; iy++, curDetPos += det_dy) {
*pImCol++ += pCubicInterp->interpolate (static_cast<double>(curDetPos) / 65536);
}
double dU = (m_dFocalLength + rsin_t) / m_dFocalLength;
double dDetPos = rcos_t / dU;
- // double to scale for imaginary detector that passes through origin
- // of phantom, see Kak-Slaney Figure 3.22. This assumes that the detector is also
- // located focal-length away from the origin.
- dDetPos *= 2;
+ // Scale for imaginary detector that passes through origin of phantom, see Kak-Slaney Figure 3.22.
+ dDetPos *= m_dSourceDetectorLength / m_dFocalLength;
double dPos = dDetPos / detInc; // position along detector array
if (interpType == Backprojector::INTERP_NEAREST) {