** This is part of the CTSim program
** Copyright (C) 1983-2000 Kevin Rosenberg
**
-** $Id: procsignal.cpp,v 1.1 2000/08/19 23:00:05 kevin Exp $
+** $Id: procsignal.cpp,v 1.6 2000/09/02 05:10:39 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 char* ProcessSignal::s_aszFilterMethodTitle[] = {
{"Convolution"},
- {"Direct Fourier"},
- {"Fouier Trigometric Table Lookout"},
+ {"Fourier"},
+ {"Fouier Trigometric Table"},
{"FFT"},
#if HAVE_FFTW
{"FFTW"},
// CLASS IDENTIFICATION
// ProcessSignal
//
-ProcessSignal::ProcessSignal (const char* szFilterName, const char* szFilterMethodName, double dBandwidth, double dSignalIncrement, int nSignalPoints, double dFilterParam, const char* szDomainName, const char* szFilterGenerationName, int iZeropad = 0, int iPreinterpolationFactor = 1)
+ProcessSignal::ProcessSignal (const char* szFilterName, const char* szFilterMethodName, double dBandwidth, double dSignalIncrement, int nSignalPoints, double dFilterParam, const char* szDomainName, const char* szFilterGenerationName, int iZeropad, int iPreinterpolationFactor, int iTraceLevel, int iGeometry, double dFocalLength, SGP* pSGP)
: m_adFourierCosTable(NULL), m_adFourierSinTable(NULL), m_adFilter(NULL), m_fail(false)
{
m_idFilterMethod = convertFilterMethodNameToID (szFilterMethodName);
return;
}
- init (m_idFilter, m_idFilterMethod, dBandwidth, dSignalIncrement, nSignalPoints, dFilterParam, m_idDomain, m_idFilterGeneration, iZeropad, iPreinterpolationFactor);
+ init (m_idFilter, m_idFilterMethod, dBandwidth, dSignalIncrement, nSignalPoints, dFilterParam, m_idDomain, m_idFilterGeneration, iZeropad, iPreinterpolationFactor, iTraceLevel, iGeometry, dFocalLength, pSGP);
}
void
-ProcessSignal::init (const int idFilter, const int idFilterMethod, double dBandwidth, double dSignalIncrement, int nSignalPoints, double dFilterParam, const int idDomain, const int idFilterGeneration, const int iZeropad, const int iPreinterpolationFactor)
+ProcessSignal::init (const int idFilter, const int idFilterMethod, double dBandwidth, double dSignalIncrement, int nSignalPoints, double dFilterParam, const int idDomain, const int idFilterGeneration, const int iZeropad, const int iPreinterpolationFactor, int iTraceLevel, int iGeometry, double dFocalLength, SGP* pSGP)
{
m_idFilter = idFilter;
m_idDomain = idDomain;
m_idFilterMethod = idFilterMethod;
m_idFilterGeneration = idFilterGeneration;
+ m_idGeometry = iGeometry;
+ m_dFocalLength = dFocalLength;
+
if (m_idFilter == SignalFilter::FILTER_INVALID || m_idDomain == SignalFilter::DOMAIN_INVALID || m_idFilterMethod == FILTER_METHOD_INVALID || m_idFilterGeneration == FILTER_GENERATION_INVALID) {
m_fail = true;
return;
}
- m_traceLevel = TRACE_NONE;
+ m_traceLevel = iTraceLevel;
m_nameFilterMethod = convertFilterMethodIDToName (m_idFilterMethod);
m_nameFilterGeneration = convertFilterGenerationIDToName (m_idFilterGeneration);
m_dBandwidth = dBandwidth;
m_iZeropad = iZeropad;
m_iPreinterpolationFactor = iPreinterpolationFactor;
+ // scale signalInc/BW to signalInc/2 to adjust for imaginary detector
+ // through origin of phantom, see Kak-Slaney Fig 3.22, for Collinear
+ if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
+ m_dSignalInc /= 2;
+ m_dBandwidth *= 2;
+ }
+
if (m_idFilterMethod == FILTER_METHOD_FFT) {
#if HAVE_FFTW
m_idFilterMethod = FILTER_METHOD_RFFTW;
if (! m_bFrequencyFiltering) {
if (m_idFilterGeneration == FILTER_GENERATION_DIRECT) {
- m_nFilterPoints = 2 * m_nSignalPoints - 1;
+ m_nFilterPoints = 2 * (m_nSignalPoints - 1) + 1;
m_dFilterMin = -m_dSignalInc * (m_nSignalPoints - 1);
m_dFilterMax = m_dSignalInc * (m_nSignalPoints - 1);
m_dFilterInc = (m_dFilterMax - m_dFilterMin) / (m_nFilterPoints - 1);
m_adFilter = new double[ m_nFilterPoints ];
filter.copyFilterData (m_adFilter, 0, m_nFilterPoints);
} else if (m_idFilterGeneration == FILTER_GENERATION_INVERSE_FOURIER) {
- m_nFilterPoints = m_nSignalPoints;
+ m_nFilterPoints = 2 * (m_nSignalPoints - 1) + 1;
m_dFilterMin = -1. / (2 * m_dSignalInc);
m_dFilterMax = 1. / (2 * m_dSignalInc);
m_dFilterInc = (m_dFilterMax - m_dFilterMin) / (m_nFilterPoints - 1);
SignalFilter filter (m_idFilter, m_dFilterMin, m_dFilterMax, m_nFilterPoints, m_dBandwidth, m_dFilterParam, SignalFilter::DOMAIN_FREQUENCY);
m_adFilter = new double[ m_nFilterPoints ];
double adFrequencyFilter [m_nFilterPoints];
- double adInverseFilter [m_nFilterPoints];
filter.copyFilterData (adFrequencyFilter, 0, m_nFilterPoints);
+ EZPlot* pEZPlot = NULL;
+ if (pSGP && m_traceLevel >= Trace::TRACE_PLOT) {
+ pEZPlot = new EZPlot (*pSGP);
+ pEZPlot->ezset ("title Filter Response: Natural Order");
+ pEZPlot->ezset ("ylength 0.25");
+ pEZPlot->addCurve (adFrequencyFilter, m_nFilterPoints);
+ pEZPlot->plot();
+ }
+
shuffleNaturalToFourierOrder (adFrequencyFilter, m_nFilterPoints);
- ProcessSignal::finiteFourierTransform (adFrequencyFilter, adInverseFilter, m_nFilterPoints, 1);
- for (int i = 0; i < m_nFilterPoints; i++)
- m_adFilter [i] = adInverseFilter[i];
- }
- }
-
- // Frequency-based filtering
- else if (m_bFrequencyFiltering) {
-
- // calculate number of filter points with zeropadding
- m_nFilterPoints = m_nSignalPoints;
- if (m_iZeropad > 0) {
- double logBase2 = log(m_nSignalPoints) / log(2);
- int nextPowerOf2 = static_cast<int>(floor(logBase2));
- if (logBase2 != floor(logBase2))
- nextPowerOf2++;
- nextPowerOf2 += (m_iZeropad - 1);
- m_nFilterPoints = 1 << nextPowerOf2;
- if (m_traceLevel >= TRACE_TEXT)
- cout << "nFilterPoints = " << m_nFilterPoints << endl;
+ if (pEZPlot && m_traceLevel >= Trace::TRACE_PLOT) {
+ pEZPlot->ezset ("title Filter Response: Fourier Order");
+ pEZPlot->ezset ("ylength 0.25");
+ pEZPlot->ezset ("yporigin 0.25");
+ pEZPlot->addCurve (adFrequencyFilter, m_nFilterPoints);
+ pEZPlot->plot();
+ }
+ ProcessSignal::finiteFourierTransform (adFrequencyFilter, m_adFilter, m_nFilterPoints, -1);
+ if (pEZPlot && m_traceLevel >= Trace::TRACE_PLOT) {
+ pEZPlot->ezset ("title Inverse Fourier Frequency: Fourier Order");
+ pEZPlot->ezset ("ylength 0.25");
+ pEZPlot->ezset ("yporigin 0.50");
+ pEZPlot->addCurve (m_adFilter, m_nFilterPoints);
+ pEZPlot->plot();
+ }
+ shuffleFourierToNaturalOrder (m_adFilter, m_nFilterPoints);
+ if (pEZPlot && m_traceLevel >= Trace::TRACE_PLOT) {
+ pEZPlot->ezset ("title Inverse Fourier Frequency: Natural Order");
+ pEZPlot->ezset ("ylength 0.25");
+ pEZPlot->ezset ("yporigin 0.75");
+ pEZPlot->addCurve (m_adFilter, m_nFilterPoints);
+ pEZPlot->plot();
+ delete pEZPlot;
+ }
+ for (int i = 0; i < m_nFilterPoints; i++) {
+ m_adFilter[i] /= m_dSignalInc;
+ }
}
- m_nOutputPoints = m_nFilterPoints * m_iPreinterpolationFactor;
+ if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
+ for (int i = 0; i < m_nFilterPoints; i++)
+ m_adFilter[i] *= 0.5;
+ } else if (m_idGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
+ for (int i = 0; i < m_nFilterPoints; i++) {
+ int iDetFromZero = i - ((m_nFilterPoints - 1) / 2);
+ double sinScale = sin (iDetFromZero * m_dSignalInc);
+ if (fabs(sinScale) < 1E-7)
+ sinScale = 1;
+ else
+ sinScale = (iDetFromZero * m_dSignalInc) / sinScale;
+ double dScale = 0.5 * sinScale * sinScale;
+ m_adFilter[i] *= dScale;
+ }
+ } // if (geometry)
+ } // if (spatial filtering)
+
+ else if (m_bFrequencyFiltering) { // Frequency-based filtering
if (m_idFilterGeneration == FILTER_GENERATION_DIRECT) {
+ // calculate number of filter points with zeropadding
+ m_nFilterPoints = m_nSignalPoints;
+ if (m_iZeropad > 0) {
+ double logBase2 = log(m_nFilterPoints) / log(2);
+ int nextPowerOf2 = static_cast<int>(floor(logBase2));
+ if (logBase2 != floor(logBase2))
+ nextPowerOf2++;
+ nextPowerOf2 += (m_iZeropad - 1);
+ m_nFilterPoints = 1 << nextPowerOf2;
+#ifdef DEBUG
+ if (m_traceLevel >= Trace::TRACE_CONSOLE)
+ cout << "nFilterPoints = " << m_nFilterPoints << endl;
+#endif
+ }
+ m_nOutputPoints = m_nFilterPoints * m_iPreinterpolationFactor;
+
+ if (m_nFilterPoints % 2) { // Odd
m_dFilterMin = -1. / (2 * m_dSignalInc);
m_dFilterMax = 1. / (2 * m_dSignalInc);
m_dFilterInc = (m_dFilterMax - m_dFilterMin) / (m_nFilterPoints - 1);
- SignalFilter filter (m_idFilter, m_dFilterMin, m_dFilterMax, m_nFilterPoints, m_dBandwidth, m_dFilterParam, SignalFilter::DOMAIN_FREQUENCY);
- m_adFilter = new double [m_nFilterPoints];
- filter.copyFilterData (m_adFilter, 0, m_nFilterPoints);
- shuffleNaturalToFourierOrder (m_adFilter, m_nFilterPoints);
+ } else { // Even
+ m_dFilterMin = -1. / (2 * m_dSignalInc);
+ m_dFilterMax = 1. / (2 * m_dSignalInc);
+ m_dFilterInc = (m_dFilterMax - m_dFilterMin) / m_nFilterPoints;
+ m_dFilterMax -= m_dFilterInc;
+ }
+
+ SignalFilter filter (m_idFilter, m_dFilterMin, m_dFilterMax, m_nFilterPoints, m_dBandwidth, m_dFilterParam, SignalFilter::DOMAIN_FREQUENCY);
+ m_adFilter = new double [m_nFilterPoints];
+ filter.copyFilterData (m_adFilter, 0, m_nFilterPoints);
+
+ if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
+ for (int i = 0; i < m_nFilterPoints; i++)
+ m_adFilter[i] *= 0.5;
+ } else if (m_idGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
+ for (int i = 0; i < m_nFilterPoints; i++) {
+ int iDetFromZero = i - ((m_nFilterPoints - 1) / 2);
+ double sinScale = sin (iDetFromZero * m_dSignalInc);
+ if (fabs(sinScale) < 1E-7)
+ sinScale = 1;
+ else
+ sinScale = (iDetFromZero * m_dSignalInc) / sinScale;
+ double dScale = 0.5 * sinScale * sinScale;
+ // m_adFilter[i] *= dScale;
+ }
+ }
+ EZPlot* pEZPlot = NULL;
+ if (pSGP && m_traceLevel >= Trace::TRACE_PLOT) {
+ pEZPlot = new EZPlot (*pSGP);
+ pEZPlot->ezset ("title Filter Filter: Natural Order");
+ pEZPlot->ezset ("ylength 0.50");
+ pEZPlot->ezset ("yporigin 0.00");
+ pEZPlot->addCurve (m_adFilter, m_nFilterPoints);
+ pEZPlot->plot();
+ }
+ shuffleNaturalToFourierOrder (m_adFilter, m_nFilterPoints);
+ if (pEZPlot && m_traceLevel >= Trace::TRACE_PLOT) {
+ pEZPlot->ezset ("title Filter Filter: Fourier Order");
+ pEZPlot->ezset ("ylength 0.50");
+ pEZPlot->ezset ("yporigin 0.50");
+ pEZPlot->addCurve (m_adFilter, m_nFilterPoints);
+ pEZPlot->plot();
+ delete pEZPlot;
+ }
} else if (m_idFilterGeneration == FILTER_GENERATION_INVERSE_FOURIER) {
- m_nFilterPoints = 2 * m_nSignalPoints - 1;
- m_dFilterMin = -m_dSignalInc * (m_nSignalPoints - 1);
- m_dFilterMax = m_dSignalInc * (m_nSignalPoints - 1);
- m_dFilterInc = (m_dFilterMax - m_dFilterMin) / (m_nFilterPoints - 1);
- double adSpatialFilter [m_nFilterPoints];
- double adInverseFilter [m_nFilterPoints];
- SignalFilter filter (m_idFilter, m_dFilterMin, m_dFilterMax, m_nFilterPoints, m_dBandwidth, m_dFilterParam, SignalFilter::DOMAIN_SPATIAL);
- filter.copyFilterData (adSpatialFilter, 0, m_nFilterPoints);
- m_adFilter = new double [m_nFilterPoints];
- finiteFourierTransform (adSpatialFilter, adInverseFilter, m_nFilterPoints, -1);
+ // calculate number of filter points with zeropadding
+ int nSpatialPoints = 2 * (m_nSignalPoints - 1) + 1;
+ m_dFilterMin = -m_dSignalInc * (m_nSignalPoints - 1);
+ m_dFilterMax = m_dSignalInc * (m_nSignalPoints - 1);
+ m_dFilterInc = (m_dFilterMax - m_dFilterMin) / (nSpatialPoints - 1);
+ m_nFilterPoints = nSpatialPoints;
+ if (m_iZeropad > 0) {
+ double logBase2 = log(nSpatialPoints) / log(2);
+ int nextPowerOf2 = static_cast<int>(floor(logBase2));
+ if (logBase2 != floor(logBase2))
+ nextPowerOf2++;
+ nextPowerOf2 += (m_iZeropad - 1);
+ m_nFilterPoints = 1 << nextPowerOf2;
+ }
+ m_nOutputPoints = m_nFilterPoints * m_iPreinterpolationFactor;
+#ifdef DEBUG
+ if (m_traceLevel >= Trace::TRACE_CONSOLE)
+ cout << "nFilterPoints = " << m_nFilterPoints << endl;
+#endif
+ double adSpatialFilter [m_nFilterPoints];
+ SignalFilter filter (m_idFilter, m_dFilterMin, m_dFilterMax, nSpatialPoints, m_dBandwidth, m_dFilterParam, SignalFilter::DOMAIN_SPATIAL);
+ filter.copyFilterData (adSpatialFilter, 0, nSpatialPoints);
+ EZPlot* pEZPlot = NULL;
+ if (pSGP && m_traceLevel >= Trace::TRACE_PLOT) {
+ pEZPlot = new EZPlot (*pSGP);
+ pEZPlot->ezset ("title Spatial Filter: Natural Order");
+ pEZPlot->ezset ("ylength 0.50");
+ pEZPlot->ezset ("yporigin 0.00");
+ pEZPlot->addCurve (adSpatialFilter, nSpatialPoints);
+ pEZPlot->plot();
+ delete pEZPlot;
+ }
+ if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
for (int i = 0; i < m_nFilterPoints; i++)
- m_adFilter [i] = adInverseFilter[i];
+ adSpatialFilter[i] *= 0.5;
+ } else if (m_idGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
+ for (int i = 0; i < m_nFilterPoints; i++) {
+ int iDetFromZero = i - ((m_nFilterPoints - 1) / 2);
+ double sinScale = sin (iDetFromZero * m_dSignalInc);
+ if (fabs(sinScale) < 1E-7)
+ sinScale = 1;
+ else
+ sinScale = (iDetFromZero * m_dSignalInc) / sinScale;
+ double dScale = 0.5 * sinScale * sinScale;
+ adSpatialFilter[i] *= dScale;
+ }
}
- }
+ for (int i = nSpatialPoints; i < m_nFilterPoints; i++)
+ adSpatialFilter[i] = 0;
+ m_adFilter = new double [m_nFilterPoints];
+ complex<double> acInverseFilter [m_nFilterPoints];
+ finiteFourierTransform (adSpatialFilter, acInverseFilter, m_nFilterPoints, 1);
+ for (int i = 0; i < m_nFilterPoints; i++)
+ m_adFilter[i] = abs(acInverseFilter[i]) * m_dSignalInc;
+ if (pEZPlot && m_traceLevel >= Trace::TRACE_PLOT) {
+ pEZPlot->ezset ("title Spatial Filter: Inverse");
+ pEZPlot->ezset ("ylength 0.50");
+ pEZPlot->ezset ("yporigin 0.50");
+ pEZPlot->addCurve (m_adFilter, m_nFilterPoints);
+ pEZPlot->plot();
+ delete pEZPlot;
+ }
+ }
+ }
+
// precalculate sin and cosine tables for fourier transform
if (m_idFilterMethod == FILTER_METHOD_FOURIER_TABLE) {
int nFourier = max(m_nFilterPoints,m_nOutputPoints) * max(m_nFilterPoints, m_nOutputPoints) + 1;
{
delete [] m_adFourierSinTable;
delete [] m_adFourierCosTable;
+ delete [] m_adFilter;
#if HAVE_FFTW
if (m_idFilterMethod == FILTER_METHOD_FFTW) {
}
void
-ProcessSignal::filterSignal (const float input[], double output[]) const
+ProcessSignal::filterSignal (const float constInput[], double output[]) const
{
+ double input [m_nSignalPoints];
+ for (int i = 0; i < m_nSignalPoints; i++)
+ input[i] = constInput[i];
+
+ if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
+ for (int i = 0; i < m_nSignalPoints; i++) {
+ int iDetFromCenter = i - (m_nSignalPoints / 2);
+ input[i] *= m_dFocalLength / sqrt (m_dFocalLength * m_dFocalLength + iDetFromCenter * iDetFromCenter * m_dSignalInc * m_dSignalInc);
+ }
+ } else if (m_idGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
+ for (int i = 0; i < m_nSignalPoints; i++) {
+ int iDetFromCenter = i - (m_nSignalPoints / 2);
+ input[i] *= m_dFocalLength * cos (iDetFromCenter * m_dSignalInc);
+ }
+ }
if (m_idFilterMethod == FILTER_METHOD_CONVOLUTION) {
- for (int i = 0; i < m_nSignalPoints; i++)
- output[i] = convolve (input, m_dSignalInc, i, m_nSignalPoints);
+ for (int i = 0; i < m_nSignalPoints; i++)
+ output[i] = convolve (input, m_dSignalInc, i, m_nSignalPoints);
} else if (m_idFilterMethod == FILTER_METHOD_FOURIER) {
double inputSignal[m_nFilterPoints];
for (int i = 0; i < m_nSignalPoints; i++)
finiteFourierTransform (input, complexOutput, n, direction);
for (int i = 0; i < n; i++)
- output[i] = abs(complexOutput[n]);
+ output[i] = complexOutput[i].real();
}
void
int iHalfN = (n - 1) / 2;
pdTemp[0] = pdVector[iHalfN];
- for (int i = 1; i <= iHalfN; i++)
- pdTemp[i] = pdVector[i+iHalfN];
- for (int i = iHalfN+1; i < n; i++)
- pdTemp[i] = pdVector[i-iHalfN];
+ for (int i = 0; i < iHalfN; i++)
+ pdTemp[i + 1] = pdVector[i + 1 + iHalfN];
+ for (int i = 0; i < iHalfN; i++)
+ pdTemp[i + iHalfN + 1] = pdVector[i];
} else { // Even
int iHalfN = n / 2;
pdTemp[0] = pdVector[iHalfN];
+ for (int i = 0; i < iHalfN; i++)
+ pdTemp[i + 1] = pdVector[i + iHalfN];
+ for (int i = 0; i < iHalfN - 1; i++)
+ pdTemp[i + iHalfN + 1] = pdVector[i];
}
for (int i = 0; i < n; i++)
int iHalfN = (n - 1) / 2;
pdTemp[iHalfN] = pdVector[0];
- for (int i = 1; i <= iHalfN; i++)
- pdTemp[i] = pdVector[i+iHalfN];
- for (int i = iHalfN+1; i < n; i++)
- pdTemp[i] = pdVector[i-iHalfN];
+ for (int i = 0; i < iHalfN; i++)
+ pdTemp[i + 1 + iHalfN] = pdVector[i + 1];
+ for (int i = 0; i < iHalfN; i++)
+ pdTemp[i] = pdVector[i + iHalfN + 1];
} else { // Even
int iHalfN = n / 2;
pdTemp[iHalfN] = pdVector[0];
+ for (int i = 0; i < iHalfN; i++)
+ pdTemp[i] = pdVector[i + iHalfN];
+ for (int i = 0; i < iHalfN - 1; i++)
+ pdTemp[i + iHalfN + 1] = pdVector[i+1];
}
for (int i = 0; i < n; i++)