** This is part of the CTSim program
** Copyright (C) 1983-2000 Kevin Rosenberg
**
-** $Id: procsignal.cpp,v 1.2 2000/08/22 07:02:48 kevin Exp $
+** $Id: procsignal.cpp,v 1.5 2000/08/31 08:38:58 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
// 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, int iTraceLevel = TRACE_NONE)
+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)
: 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, iTraceLevel);
+ init (m_idFilter, m_idFilterMethod, dBandwidth, dSignalIncrement, nSignalPoints, dFilterParam, m_idDomain, m_idFilterGeneration, iZeropad, iPreinterpolationFactor, iTraceLevel, iGeometry, dFocalLength);
}
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, int iTraceLevel)
+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)
{
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_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;
m_adFilter = new double[ m_nFilterPoints ];
double adFrequencyFilter [m_nFilterPoints];
filter.copyFilterData (adFrequencyFilter, 0, m_nFilterPoints);
- if (m_traceLevel >= TRACE_PLOT) {
+ if (m_traceLevel >= Trace::TRACE_PLOT) {
SGPDriver sgpDriver ("Frequency Filter: Natural Order");
SGP sgp (sgpDriver);
EZPlot ezplot (sgp);
}
shuffleNaturalToFourierOrder (adFrequencyFilter, m_nFilterPoints);
- if (m_traceLevel >= TRACE_PLOT) {
+ if (m_traceLevel >= Trace::TRACE_PLOT) {
SGPDriver sgpDriver ("Frequency Filter: Fourier Order");
SGP sgp (sgpDriver);
EZPlot ezplot (sgp);
cio_kb_getc ();
}
ProcessSignal::finiteFourierTransform (adFrequencyFilter, m_adFilter, m_nFilterPoints, -1);
- if (m_traceLevel >= TRACE_PLOT) {
+ if (m_traceLevel >= Trace::TRACE_PLOT) {
SGPDriver sgpDriver ("Inverse Fourier Frequency: Fourier Order");
SGP sgp (sgpDriver);
EZPlot ezplot (sgp);
cio_kb_getc ();
}
shuffleFourierToNaturalOrder (m_adFilter, m_nFilterPoints);
- if (m_traceLevel >= TRACE_PLOT) {
+ if (m_traceLevel >= Trace::TRACE_PLOT) {
SGPDriver sgpDriver ("Inverse Fourier Frequency: Natural Order");
SGP sgp (sgpDriver);
EZPlot ezplot (sgp);
m_adFilter[i] /= m_dSignalInc;
}
}
- }
+ 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)
- // Frequency-based filtering
- else if (m_bFrequencyFiltering) {
+ else if (m_bFrequencyFiltering) { // Frequency-based filtering
if (m_idFilterGeneration == FILTER_GENERATION_DIRECT) {
// calculate number of filter points with zeropadding
nextPowerOf2++;
nextPowerOf2 += (m_iZeropad - 1);
m_nFilterPoints = 1 << nextPowerOf2;
- if (m_traceLevel >= TRACE_TEXT)
+ if (m_traceLevel >= Trace::TRACE_CONSOLE)
cout << "nFilterPoints = " << m_nFilterPoints << endl;
}
m_nOutputPoints = m_nFilterPoints * m_iPreinterpolationFactor;
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_traceLevel >= TRACE_PLOT) {
+
+ 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 (m_traceLevel >= Trace::TRACE_PLOT) {
SGPDriver sgpDriver ("Frequency Filter: Natural Order");
SGP sgp (sgpDriver);
EZPlot ezplot (sgp);
cio_kb_getc ();
}
shuffleNaturalToFourierOrder (m_adFilter, m_nFilterPoints);
- if (m_traceLevel >= TRACE_PLOT) {
+ if (m_traceLevel >= Trace::TRACE_PLOT) {
SGPDriver sgpDriver ("Frequency Filter: Fourier Order");
SGP sgp (sgpDriver);
EZPlot ezplot (sgp);
m_nFilterPoints = 1 << nextPowerOf2;
}
m_nOutputPoints = m_nFilterPoints * m_iPreinterpolationFactor;
- if (m_traceLevel >= TRACE_TEXT)
+ if (m_traceLevel >= Trace::TRACE_CONSOLE)
cout << "nFilterPoints = " << m_nFilterPoints << endl;
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);
- if (m_traceLevel >= TRACE_PLOT) {
+ if (m_traceLevel >= Trace::TRACE_PLOT) {
SGPDriver sgpDriver ("Spatial Filter: Natural Order");
SGP sgp (sgpDriver);
EZPlot ezplot (sgp);
cio_put_str ("Press any key to continue");
cio_kb_getc ();
}
+ if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
+ for (int i = 0; i < m_nFilterPoints; 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;
finiteFourierTransform (adSpatialFilter, acInverseFilter, m_nFilterPoints, 1);
for (int i = 0; i < m_nFilterPoints; i++)
m_adFilter[i] = abs(acInverseFilter[i]) * m_dSignalInc;
- if (m_traceLevel >= TRACE_PLOT) {
+ if (m_traceLevel >= Trace::TRACE_PLOT) {
SGPDriver sgpDriver ("Spatial Filter: Inverse");
SGP sgp (sgpDriver);
EZPlot ezplot (sgp);
}
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++)