** This is part of the CTSim program
** Copyright (c) 1983-2001 Kevin Rosenberg
**
-** $Id: projections.cpp,v 1.59 2001/03/11 15:27:30 kevin Exp $
+** $Id: projections.cpp,v 1.64 2001/03/13 09:25:18 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
if (! v || nx == 0 || ny == 0)
return false;
- if (m_geometry != Scanner::GEOMETRY_PARALLEL) {
- sys_error (ERR_WARNING, "convertPolar supports Parallel only");
- return false;
- }
+ Projections* pProj = this;
+ if (m_geometry == Scanner::GEOMETRY_EQUIANGULAR || m_geometry == Scanner::GEOMETRY_EQUILINEAR)
+ pProj = interpolateToParallel();
Array2d<double> adView (nx, ny);
Array2d<double> adDet (nx, ny);
double** ppdView = adView.getArray();
double** ppdDet = adDet.getArray();
- if (! calcArrayPolarCoordinates (nx, ny, ppdView, ppdDet))
+ if (! pProj->calcArrayPolarCoordinates (nx, ny, ppdView, ppdDet))
return false;
std::complex<double>** ppcDetValue = new std::complex<double>* [m_nView];
for (iView = 0; iView < m_nView; iView++) {
ppcDetValue[iView] = new std::complex<double> [m_nDet];
for (unsigned int iDet = 0; iDet < m_nDet; iDet++)
- ppcDetValue[iView][iDet] = std::complex<double>(getDetectorArray (iView).detValues()[iDet], 0);
+ ppcDetValue[iView][iDet] = std::complex<double>(pProj->getDetectorArray (iView).detValues()[iDet], 0);
}
- interpolatePolar (v, vImag, nx, ny, ppcDetValue, ppdView, ppdDet, m_nView, m_nDet, iInterpolationID);
+ pProj->interpolatePolar (v, vImag, nx, ny, ppcDetValue, ppdView, ppdDet, pProj->m_nView, pProj->m_nDet, iInterpolationID);
for (iView = 0; iView < m_nView; iView++)
delete [] ppcDetValue[iView];
delete [] ppcDetValue;
+ if (m_geometry == Scanner::GEOMETRY_EQUIANGULAR || m_geometry == Scanner::GEOMETRY_EQUILINEAR)
+ delete pProj;
+
return true;
}
{
init (iNViews, iNDets);
m_geometry = Scanner::GEOMETRY_EQUIANGULAR;
- m_dFanBeamAngle = iNDets * convertDegreesToRadians (3.06976 / 60);
m_dFocalLength = 510;
m_dSourceDetectorLength = 890;
m_detInc = convertDegreesToRadians (3.06976 / 60);
- m_detStart = -m_dFanBeamAngle / 2;
+ m_dFanBeamAngle = iNDets * m_detInc;
+ m_detStart = -(m_dFanBeamAngle / 2);
m_rotInc = TWOPI / static_cast<double>(iNViews);
- m_rotStart = HALFPI;
+ m_rotStart = 0;
m_dViewDiameter = sin (m_dFanBeamAngle / 2) * m_dFocalLength * 2;
- if (iNDets != 1024)
- return false;
- bool bValid = (iNViews == 750 && lDataLength == 1560000L) || (iNViews == 950 && lDataLength == 1976000L) || (iNViews == 1500 && lDataLength == 3120000);
- if (! bValid)
+ if (! ((iNViews == 750 && lDataLength == 1560000L) || (iNViews == 950 && lDataLength == 1976000L)
+ || (iNViews == 1500 && lDataLength == 3120000)))
return false;
+ double dCenter = (iNDets - 1.) / 2.; // change from (Nm+1)/2 because of 0 vs. 1 indexing
+ double* pdCosScale = new double [iNDets];
+ for (int i = 0; i < iNDets; i++)
+ pdCosScale[i] = 1. / cos ((i - dCenter) * m_detInc);
+
long lDataPos = 0;
for (int iv = 0; iv < iNViews; iv++) {
unsigned char* pArgBase = pData + lDataPos;
- unsigned char* p = pArgBase+0;
-#ifndef WORDS_BIGENDIAN
- SwapBytes4 (p);
-#endif
+ unsigned char* p = pArgBase+0; SwapBytes4IfLittleEndian (p);
long lProjNumber = *reinterpret_cast<long*>(p);
- p = pArgBase+20;
-#ifndef WORDS_BIGENDIAN
- SwapBytes4 (p);
-#endif
+ p = pArgBase+20; SwapBytes4IfLittleEndian (p);
long lEscale = *reinterpret_cast<long*>(p);
- p = pArgBase+28;
-#ifndef WORDS_BIGENDIAN
- SwapBytes4 (p);
-#endif
+ p = pArgBase+28; SwapBytes4IfLittleEndian (p);
long lTime = *reinterpret_cast<long*>(p);
- p = pArgBase + 4;
-#ifndef WORDS_BIGENDIAN
- SwapBytes4 (p);
-#endif
+ p = pArgBase + 4; SwapBytes4IfLittleEndian (p);
double dAlpha = *reinterpret_cast<float*>(p) + HALFPI;
- p = pArgBase+12;
-#ifndef WORDS_BIGENDIAN
- SwapBytes4 (p);
-#endif
+ p = pArgBase+12; SwapBytes4IfLittleEndian (p);
double dAlign = *reinterpret_cast<float*>(p);
- p = pArgBase + 16;
-#ifndef WORDS_BIGENDIAN
- SwapBytes4 (p);
-#endif
+ p = pArgBase + 16; SwapBytes4IfLittleEndian (p);
double dMaxValue = *reinterpret_cast<float*>(p);
- lDataPos += 32;
- double dEScale = pow (2.0, -lEscale);
- double dBetaInc = convertDegreesToRadians (3.06976 / 60);
- int iCenter = (iNDets + 1) / 2;
-
- DetectorArray& detArray = getDetectorArray( iv );
+ DetectorArray& detArray = getDetectorArray (iv);
detArray.setViewAngle (dAlpha);
DetectorValue* detval = detArray.detValues();
- double dTempScale = 2294.4871 * dEScale;
+ double dViewScale = 1. / (2294.4871 * ::pow (2.0, -lEscale));
+ lDataPos += 32;
for (int id = 0; id < iNDets; id++) {
- int iV = pData[lDataPos+1] + 256 * pData[lDataPos];
+ int iV = pData[lDataPos+1] + (pData[lDataPos] << 8);
if (iV > 32767) // two's complement signed conversion
iV = iV - 65536;
- double dCosScale = cos ((id + 1 - iCenter) * dBetaInc);
- detval[id] = iV / (dTempScale * dCosScale);
+ detval[id] = iV * dViewScale * pdCosScale[id];
lDataPos += 2;
}
+#if 1
+ for (int k = iNDets - 2; k >= 0; k--)
+ detval[k+1] = detval[k];
+ detval[0] = 0;
+#endif
}
+ delete pdCosScale;
return true;
}
Projections*
-Projections::interpolateToParallel ()
+Projections::interpolateToParallel () const
{
if (m_geometry == Scanner::GEOMETRY_PARALLEL)
- return this;
+ return const_cast<Projections*>(this);
int nDet = m_nDet;
int nView = m_nView;
if (nDet % 2 == 0) // even
pProjNew->m_detInc = m_dViewDiameter / (nDet - 1);
- ParallelRaysums parallel (this);
+ ParallelRaysums parallel (this, ParallelRaysums::THETA_RANGE_NORMALIZE_TO_TWOPI);
double* pdThetaValuesForT = new double [pProjNew->nView()];
double* pdRaysumsForT = new double [pProjNew->nView()];
parallel.getThetaAndRaysumsForT (iD, pdThetaValuesForT, pdRaysumsForT);
double dViewAngle = m_rotStart;
+ int iLastFloor = -1;
for (int iV = 0; iV < pProjNew->nView(); iV++, dViewAngle += pProjNew->m_rotInc) {
DetectorValue* detValues = pProjNew->getDetectorArray (iV).detValues();
- detValues[iD] = parallel.interpolate (pdThetaValuesForT, pdRaysumsForT, pProjNew->nView(), dViewAngle);
+ detValues[iD] = parallel.interpolate (pdThetaValuesForT, pdRaysumsForT, pProjNew->nView(), dViewAngle, &iLastFloor);
}
}
delete pdThetaValuesForT;
pdDetValueCopy[i] = detValues[i];
double dDetPos = pProjNew->m_detStart;
+ int iLastFloor = -1;
for (int iD = 0; iD < pProjNew->nDet(); iD++, dDetPos += pProjNew->m_detInc) {
- detValues[iD] = parallel.interpolate (pdOriginalDetPositions, pdDetValueCopy, pProjNew->nDet(), dDetPos);
+ detValues[iD] = parallel.interpolate (pdOriginalDetPositions, pdDetValueCopy, pProjNew->nDet(), dDetPos, &iLastFloor);
}
}
delete pdDetValueCopy;
//
///////////////////////////////////////////////////////////////////////////////
-ParallelRaysums::ParallelRaysums (Projections* pProjections)
-: m_iNumCoordinates(0), m_iNumView(pProjections->nView()), m_iNumDet(pProjections->nDet())
+ParallelRaysums::ParallelRaysums (const Projections* pProjections, int iThetaRange)
+: m_iNumCoordinates(0), m_iNumView(pProjections->nView()), m_iNumDet(pProjections->nDet()),
+ m_iThetaRange (iThetaRange), m_pCoordinates(NULL)
{
int iGeometry = pProjections->geometry();
double dDetInc = pProjections->detInc();
double dFocalLength = pProjections->focalLength();
m_iNumCoordinates = m_iNumView * m_iNumDet;
+ m_pCoordinates = new ParallelRaysumCoordinate [m_iNumCoordinates];
m_vecpCoordinates.reserve (m_iNumCoordinates);
for (int i = 0; i < m_iNumCoordinates; i++)
- m_vecpCoordinates[i] = new ParallelRaysumCoordinate;
+ m_vecpCoordinates[i] = m_pCoordinates + i;
int iCoordinate = 0;
for (int iV = 0; iV < m_iNumView; iV++) {
ParallelRaysumCoordinate* pC = m_vecpCoordinates[iCoordinate++];
if (iGeometry == Scanner::GEOMETRY_PARALLEL) {
- pC->m_dTheta = normalizeAngle (dViewAngle);
+ pC->m_dTheta = dViewAngle;
pC->m_dT = dDetPos;
} else if (iGeometry == Scanner::GEOMETRY_EQUILINEAR) {
double dFanAngle = atan (dDetPos / pProjections->sourceDetectorLength());
- pC->m_dTheta = normalizeAngle (dViewAngle + dFanAngle);
+ pC->m_dTheta = dViewAngle + dFanAngle;
pC->m_dT = dFocalLength * sin(dFanAngle);
} else if (iGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
// fan angle is same as dDetPos
- pC->m_dTheta = normalizeAngle (dViewAngle + dDetPos);
+ pC->m_dTheta = dViewAngle + dDetPos;
pC->m_dT = dFocalLength * sin (dDetPos);
}
-#ifdef CONVERT_PARALLEL_PI
- if (pC->m_dTheta >= PI) { // convert T/Theta to 0-PI interval
- pC->m_dTheta -= PI;
- pC->m_dT = -pC->m_dT;
+ if (m_iThetaRange != THETA_RANGE_UNCONSTRAINED) {
+ pC->m_dTheta = normalizeAngle (pC->m_dTheta);
+ if (m_iThetaRange == THETA_RANGE_FOLD_TO_PI && pC->m_dTheta >= PI) {
+ pC->m_dTheta -= PI;
+ pC->m_dT = -pC->m_dT;
+ }
}
-#endif
pC->m_dRaysum = detValues[iD];
dDetPos += dDetInc;
}
ParallelRaysums::~ParallelRaysums()
{
- for (int i = 0; i < m_iNumCoordinates; i++)
- delete m_vecpCoordinates[i];
+ delete m_pCoordinates;
}
ParallelRaysums::CoordinateContainer&
}
// locate by bisection, O(log2(n))
+// iLastFloor is used when sequential calls to interpolate have monotonically increasing dX
double
-ParallelRaysums::interpolate (double* pdX, double* pdY, int n, double dX)
+ParallelRaysums::interpolate (double* pdX, double* pdY, int n, double dX, int* iLastFloor)
{
int iLower = -1;
int iUpper = n;
+ if (iLastFloor && *iLastFloor >= 0 && pdX[*iLastFloor] < dX)
+ iLower = *iLastFloor;
while (iUpper - iLower > 1) {
int iMiddle = (iUpper + iLower) >> 1;
return 0;
}
+ if (iLastFloor)
+ *iLastFloor = iLower;
return pdY[iLower] + (pdY[iUpper] - pdY[iLower]) * ((dX - pdX[iLower]) / (pdX[iUpper] - pdX[iLower]));
}