/*****************************************************************************
** File IDENTIFICATION
-**
-** Name: filter.cpp
-** Purpose: Routines for signal-procesing filters
-** Progammer: Kevin Rosenberg
-** Date Started: Aug 1984
**
-** This is part of the CTSim program
-** Copyright (C) 1983-2000 Kevin Rosenberg
+** Name: procsignal.cpp
+** Purpose: Routines for processing signals and projections
+** Progammer: Kevin Rosenberg
+** Date Started: Aug 1984
**
-** $Id: procsignal.cpp,v 1.11 2000/12/29 15:45:06 kevin Exp $
+** This is part of the CTSim program
+** Copyright (c) 1983-2009 Kevin Rosenberg
**
** 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"
+#ifdef HAVE_WXWINDOWS
+#include "nographics.h"
+#endif
+
// FilterMethod ID/Names
const int ProcessSignal::FILTER_METHOD_INVALID = -1;
const int ProcessSignal::FILTER_METHOD_CONVOLUTION = 0;
const int ProcessSignal::FILTER_METHOD_FFTW = 4;
const int ProcessSignal::FILTER_METHOD_RFFTW =5 ;
#endif
-const char* ProcessSignal::s_aszFilterMethodName[] = {
- {"convolution"},
- {"fourier"},
- {"fouier_table"},
- {"fft"},
+const char* const ProcessSignal::s_aszFilterMethodName[] = {
+ "convolution",
+ "fourier",
+ "fouier-table",
+ "fft",
#if HAVE_FFTW
- {"fftw"},
- {"rfftw"},
+ "fftw",
+ "rfftw",
#endif
};
-const char* ProcessSignal::s_aszFilterMethodTitle[] = {
- {"Convolution"},
- {"Fourier"},
- {"Fouier Trigometric Table"},
- {"FFT"},
+const char* const ProcessSignal::s_aszFilterMethodTitle[] = {
+ "Convolution",
+ "Fourier",
+ "Fouier Trigometric Table",
+ "FFT",
#if HAVE_FFTW
- {"FFTW"},
- {"Real/Half-Complex FFTW"},
+ "FFTW",
+ "Real/Half-Complex FFTW",
#endif
};
const int ProcessSignal::s_iFilterMethodCount = sizeof(s_aszFilterMethodName) / sizeof(const char*);
const int ProcessSignal::FILTER_GENERATION_INVALID = -1;
const int ProcessSignal::FILTER_GENERATION_DIRECT = 0;
const int ProcessSignal::FILTER_GENERATION_INVERSE_FOURIER = 1;
-const char* ProcessSignal::s_aszFilterGenerationName[] = {
- {"direct"},
- {"inverse_fourier"},
+const char* const ProcessSignal::s_aszFilterGenerationName[] = {
+ "direct",
+ "inverse-fourier",
};
-const char* ProcessSignal::s_aszFilterGenerationTitle[] = {
- {"Direct"},
- {"Inverse Fourier"},
+const char* const ProcessSignal::s_aszFilterGenerationTitle[] = {
+ "Direct",
+ "Inverse Fourier",
};
const int ProcessSignal::s_iFilterGenerationCount = sizeof(s_aszFilterGenerationName) / sizeof(const char*);
// 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, int iPreinterpolationFactor, int iTraceLevel, int iGeometry, double dFocalLength, SGP* pSGP)
-: m_adFourierCosTable(NULL), m_adFourierSinTable(NULL), m_adFilter(NULL), m_fail(false)
+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, double dSourceDetectorLength, SGP* pSGP)
+ : m_adFourierCosTable(NULL), m_adFourierSinTable(NULL), m_adFilter(NULL), m_fail(false)
{
m_idFilterMethod = convertFilterMethodNameToID (szFilterMethodName);
if (m_idFilterMethod == FILTER_METHOD_INVALID) {
m_failMessage += szDomainName;
return;
}
-
- init (m_idFilter, m_idFilterMethod, dBandwidth, dSignalIncrement, nSignalPoints, dFilterParam, m_idDomain, m_idFilterGeneration, iZeropad, iPreinterpolationFactor, iTraceLevel, iGeometry, dFocalLength, pSGP);
+
+ init (m_idFilter, m_idFilterMethod, dBandwidth, dSignalIncrement, nSignalPoints, dFilterParam, m_idDomain,
+ m_idFilterGeneration, iZeropad, iPreinterpolationFactor, iTraceLevel, iGeometry, dFocalLength,
+ dSourceDetectorLength, 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, int iTraceLevel, int iGeometry, double dFocalLength, SGP* pSGP)
-{\r
+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, double dSourceDetectorLength, SGP* pSGP)
+{
int i;
m_idFilter = idFilter;
m_idDomain = idDomain;
m_idFilterGeneration = idFilterGeneration;
m_idGeometry = iGeometry;
m_dFocalLength = dFocalLength;
-
+ m_dSourceDetectorLength = dSourceDetectorLength;
+
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_dBandwidth = dBandwidth;
m_nSignalPoints = nSignalPoints;
m_dSignalInc = dSignalIncrement;
- m_dFilterParam = dFilterParam;
+ m_dFilterParam = dFilterParam;
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
+
+ // scale signalInc/BW to adjust for imaginary detector through origin of phantom
+ // see Kak-Slaney Fig 3.22, for Collinear diagram
if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
- m_dSignalInc /= 2;
- m_dBandwidth *= 2;
+ double dEquilinearScale = m_dSourceDetectorLength / m_dFocalLength;
+ m_dSignalInc /= dEquilinearScale;
+ m_dBandwidth *= dEquilinearScale;
}
-
+
if (m_idFilterMethod == FILTER_METHOD_FFT) {
#if HAVE_FFTW
m_idFilterMethod = FILTER_METHOD_RFFTW;
return;
#endif
}
-
+
bool m_bFrequencyFiltering = true;
if (m_idFilterMethod == FILTER_METHOD_CONVOLUTION)
m_bFrequencyFiltering = false;
-
+
// Spatial-based filtering
if (! m_bFrequencyFiltering) {
-
+
if (m_idFilterGeneration == FILTER_GENERATION_DIRECT) {
m_nFilterPoints = 2 * (m_nSignalPoints - 1) + 1;
m_dFilterMin = -m_dSignalInc * (m_nSignalPoints - 1);
m_adFilter = new double[ m_nFilterPoints ];
double* adFrequencyFilter = new double [m_nFilterPoints];
filter.copyFilterData (adFrequencyFilter, 0, m_nFilterPoints);
-#ifdef HAVE_SGP
- EZPlot* pEZPlot = NULL;
- if (pSGP && m_traceLevel >= Trace::TRACE_PLOT) {
- pEZPlot = new EZPlot ();
- pEZPlot->ezset ("title Filter Response: Natural Order");
- pEZPlot->ezset ("ylength 0.25");
- pEZPlot->addCurve (adFrequencyFilter, m_nFilterPoints);
- pEZPlot->plot (pSGP);
+#if defined(HAVE_WXWINDOWS) && (defined(DEBUG) || defined(_DEBUG))
+ if (g_bRunningWXWindows && m_traceLevel > 0) {
+ EZPlotDialog dlgEZPlot;
+ dlgEZPlot.getEZPlot()->ezset ("title Filter Response: Natural Order");
+ dlgEZPlot.getEZPlot()->addCurve (adFrequencyFilter, m_nFilterPoints);
+ dlgEZPlot.ShowModal();
}
-#endif
- shuffleNaturalToFourierOrder (adFrequencyFilter, m_nFilterPoints);
+#endif
+ Fourier::shuffleNaturalToFourierOrder (adFrequencyFilter, m_nFilterPoints);
#ifdef HAVE_SGP
- 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 (pSGP);
+ if (g_bRunningWXWindows && m_traceLevel > 0) {
+ EZPlotDialog dlgEZPlot;
+ dlgEZPlot.getEZPlot()->ezset ("title Filter Response: Fourier Order");
+ dlgEZPlot.getEZPlot()->addCurve (adFrequencyFilter, m_nFilterPoints);
+ dlgEZPlot.ShowModal();
}
#endif
- ProcessSignal::finiteFourierTransform (adFrequencyFilter, m_adFilter, m_nFilterPoints, -1);
- delete adFrequencyFilter;\r
-#ifdef HAVE_SGP
- 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 (pSGP);
+ ProcessSignal::finiteFourierTransform (adFrequencyFilter, m_adFilter, m_nFilterPoints, FORWARD);
+ delete adFrequencyFilter;
+#if defined(HAVE_WXWINDOWS) && (defined(DEBUG) || defined(_DEBUG))
+ if (g_bRunningWXWindows && m_traceLevel > 0) {
+ EZPlotDialog dlgEZPlot;
+ dlgEZPlot.getEZPlot()->ezset ("title Inverse Fourier Frequency: Fourier Order");
+ dlgEZPlot.getEZPlot()->addCurve (m_adFilter, m_nFilterPoints);
+ dlgEZPlot.ShowModal();
}
#endif
- shuffleFourierToNaturalOrder (m_adFilter, m_nFilterPoints);
-#ifdef HAVE_SGP
- 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 (pSGP);
- delete pEZPlot;
+ Fourier::shuffleFourierToNaturalOrder (m_adFilter, m_nFilterPoints);
+#if defined(HAVE_WXWINDOWS) && (defined(DEBUG) || defined(_DEBUG))
+ if (g_bRunningWXWindows && m_traceLevel > 0) {
+ EZPlotDialog dlgEZPlot;
+ dlgEZPlot.getEZPlot()->ezset ("title Inverse Fourier Frequency: Natural Order");
+ dlgEZPlot.getEZPlot()->addCurve (m_adFilter, m_nFilterPoints);
+ dlgEZPlot.ShowModal();
}
#endif
for (i = 0; i < m_nFilterPoints; i++) {
} else if (m_idGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
for (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 sinScale = 1 / SignalFilter::sinc (iDetFromZero * m_dSignalInc);
double dScale = 0.5 * sinScale * sinScale;
m_adFilter[i] *= dScale;
}
+#if defined(HAVE_WXWINDOWS) && (defined(DEBUG) || defined(_DEBUG))
+ if (g_bRunningWXWindows && m_traceLevel > 0) {
+ EZPlotDialog dlgEZPlot;
+ dlgEZPlot.getEZPlot()->ezset ("title Scaled Inverse Fourier Frequency: Natural Order");
+ dlgEZPlot.getEZPlot()->addCurve (m_adFilter, m_nFilterPoints);
+ dlgEZPlot.ShowModal();
+ }
+#endif
} // 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)
- std::cout << "nFilterPoints = " << m_nFilterPoints << endl;
-#endif
- }
+ m_nFilterPoints = addZeropadFactor (m_nSignalPoints, m_iZeropad);
m_nOutputPoints = m_nFilterPoints * m_iPreinterpolationFactor;
-
- if (m_nFilterPoints % 2) { // Odd
+
+ if (isOdd (m_nFilterPoints)) { // Odd
m_dFilterMin = -1. / (2 * m_dSignalInc);
m_dFilterMax = 1. / (2 * m_dSignalInc);
m_dFilterInc = (m_dFilterMax - m_dFilterMin) / (m_nFilterPoints - 1);
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);
+
+ 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);
-
- // This doesn't work!
- // Need to add filtering for divergent geometries & Frequency/Direct filtering
+
+#if defined(HAVE_WXWINDOWS) && (defined(DEBUG) || defined(_DEBUG))
+ if (g_bRunningWXWindows && m_traceLevel > 0) {
+ EZPlotDialog dlgEZPlot;
+ dlgEZPlot.getEZPlot()->ezset ("title Frequency Filter: Natural Order");
+ dlgEZPlot.getEZPlot()->addCurve (m_adFilter, m_nFilterPoints);
+ dlgEZPlot.ShowModal();
+ }
+#endif
+
+ // This works fairly well. I'm not sure why since scaling for geometries is done on
+ // frequency filter rather than spatial filter as it should be.
+ // It gives values slightly off than freq/inverse filtering
if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
for (i = 0; i < m_nFilterPoints; i++)
m_adFilter[i] *= 0.5;
} else if (m_idGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
for (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 sinScale = 1 / SignalFilter::sinc (iDetFromZero * m_dSignalInc);
double dScale = 0.5 * sinScale * sinScale;
m_adFilter[i] *= dScale;
}
}
-#ifdef HAVE_SGP
- EZPlot* pEZPlot = NULL;
- if (pSGP && m_traceLevel >= Trace::TRACE_PLOT) {
- pEZPlot = new EZPlot;
- 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 (pSGP);
+#if defined(HAVE_WXWINDOWS) && (defined(DEBUG) || defined(_DEBUG))
+ if (g_bRunningWXWindows && m_traceLevel > 0) {
+ EZPlotDialog dlgEZPlot;
+ dlgEZPlot.getEZPlot()->ezset ("title Filter Geometry Scaled: Natural Order");
+ dlgEZPlot.getEZPlot()->addCurve (m_adFilter, m_nFilterPoints);
+ dlgEZPlot.ShowModal();
}
#endif
- shuffleNaturalToFourierOrder (m_adFilter, m_nFilterPoints);
-#ifdef HAVE_SGP
- 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 (pSGP);
- delete pEZPlot;
+ Fourier::shuffleNaturalToFourierOrder (m_adFilter, m_nFilterPoints);
+#if defined(HAVE_WXWINDOWS) && (defined(DEBUG) || defined(_DEBUG))
+ if (g_bRunningWXWindows && m_traceLevel > 0) {
+ EZPlotDialog dlgEZPlot;
+ dlgEZPlot.getEZPlot()->ezset ("title Filter Geometry Scaled: Fourier Order");
+ dlgEZPlot.getEZPlot()->addCurve (m_adFilter, m_nFilterPoints);
+ dlgEZPlot.ShowModal();
}
#endif
+
+ // FILTERING: FREQUENCY - INVERSE FOURIER
+
} else if (m_idFilterGeneration == FILTER_GENERATION_INVERSE_FOURIER) {
// calculate number of filter points with zeropadding
int nSpatialPoints = 2 * (m_nSignalPoints - 1) + 1;
m_nFilterPoints = 1 << nextPowerOf2;
}
m_nOutputPoints = m_nFilterPoints * m_iPreinterpolationFactor;
-#ifdef DEBUG
+#if defined(DEBUG) || defined(_DEBUG)
if (m_traceLevel >= Trace::TRACE_CONSOLE)
- std::cout << "nFilterPoints = " << m_nFilterPoints << endl;
+ sys_error (ERR_TRACE, "nFilterPoints = %d", m_nFilterPoints);
#endif
- double* adSpatialFilter = new double [m_nFilterPoints];\r
- SignalFilter filter (m_idFilter, m_dFilterMin, m_dFilterMax, nSpatialPoints, m_dBandwidth, m_dFilterParam, SignalFilter::DOMAIN_SPATIAL);
+ double* adSpatialFilter = new double [m_nFilterPoints];
+ SignalFilter filter (m_idFilter, m_dFilterMin, m_dFilterMax, nSpatialPoints, m_dBandwidth,
+ m_dFilterParam, SignalFilter::DOMAIN_SPATIAL);
filter.copyFilterData (adSpatialFilter, 0, nSpatialPoints);
-#ifdef HAVE_SGP
- EZPlot* pEZPlot = NULL;
- if (pSGP && m_traceLevel >= Trace::TRACE_PLOT) {
- pEZPlot = new EZPlot;
- pEZPlot->ezset ("title Spatial Filter: Natural Order");
- pEZPlot->ezset ("ylength 0.50");
- pEZPlot->ezset ("yporigin 0.00");
- pEZPlot->addCurve (adSpatialFilter, nSpatialPoints);
- pEZPlot->plot (pSGP);
- delete pEZPlot;
+#if defined(HAVE_WXWINDOWS) && (defined(DEBUG) || defined(_DEBUG))
+ if (g_bRunningWXWindows && m_traceLevel > 0) {
+ EZPlotDialog dlgEZPlot;;
+ dlgEZPlot.getEZPlot()->ezset ("title Spatial Filter: Natural Order");
+ dlgEZPlot.getEZPlot()->addCurve (adSpatialFilter, nSpatialPoints);
+ dlgEZPlot.ShowModal();
}
#endif
+
if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
- for (i = 0; i < m_nFilterPoints; i++)
+ for (i = 0; i < nSpatialPoints; i++)
adSpatialFilter[i] *= 0.5;
} else if (m_idGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
- for (i = 0; i < m_nFilterPoints; i++) {
- int iDetFromZero = i - ((m_nFilterPoints - 1) / 2);
+ for (i = 0; i < nSpatialPoints; i++) {
+ int iDetFromZero = i - ((nSpatialPoints - 1) / 2);
double sinScale = sin (iDetFromZero * m_dSignalInc);
if (fabs(sinScale) < 1E-7)
sinScale = 1;
double dScale = 0.5 * sinScale * sinScale;
adSpatialFilter[i] *= dScale;
}
- }\r
+ }
+#if defined(HAVE_WXWINDOWS) && (defined(DEBUG) || defined(_DEBUG))
+ if (g_bRunningWXWindows && m_traceLevel > 0) {
+ EZPlotDialog dlgEZPlot;;
+ dlgEZPlot.getEZPlot()->ezset ("title Scaled Spatial Filter: Natural Order");
+ dlgEZPlot.getEZPlot()->addCurve (adSpatialFilter, nSpatialPoints);
+ dlgEZPlot.ShowModal();
+ }
+#endif
for (i = nSpatialPoints; i < m_nFilterPoints; i++)
adSpatialFilter[i] = 0;
-
+
m_adFilter = new double [m_nFilterPoints];
- std::complex<double>* acInverseFilter = new std::complex<double> [m_nFilterPoints];\r
- finiteFourierTransform (adSpatialFilter, acInverseFilter, m_nFilterPoints, 1);
- delete adSpatialFilter;\r
+ std::complex<double>* acInverseFilter = new std::complex<double> [m_nFilterPoints];
+ finiteFourierTransform (adSpatialFilter, acInverseFilter, m_nFilterPoints, BACKWARD);
+ delete adSpatialFilter;
for (i = 0; i < m_nFilterPoints; i++)
- m_adFilter[i] = std::abs(acInverseFilter[i]) * m_dSignalInc;
- delete acInverseFilter;\r
-#ifdef HAVE_SGP
- 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 (pSGP);
- delete pEZPlot;\r
+ m_adFilter[i] = std::abs (acInverseFilter[i]) * m_dSignalInc;
+ delete acInverseFilter;
+#if defined(HAVE_WXWINDOWS) && (defined(DEBUG) || defined(_DEBUG))
+ if (g_bRunningWXWindows && m_traceLevel > 0) {
+ EZPlotDialog dlgEZPlot;
+ dlgEZPlot.getEZPlot()->ezset ("title Fourier Scaled Spatial Filter: Fourier Order");
+ dlgEZPlot.getEZPlot()->addCurve (m_adFilter, m_nFilterPoints);
+ dlgEZPlot.ShowModal();
}
#endif
}
}
-
+
// precalculate sin and cosine tables for fourier transform
if (m_idFilterMethod == FILTER_METHOD_FOURIER_TABLE) {
int nFourier = imax (m_nFilterPoints,m_nOutputPoints) * imax (m_nFilterPoints, m_nOutputPoints) + 1;
angle += angleIncrement;
}
}
-
+
#if HAVE_FFTW
if (m_idFilterMethod == FILTER_METHOD_FFTW || m_idFilterMethod == FILTER_METHOD_RFFTW) {
for (i = 0; i < m_nFilterPoints; i++) //fftw uses unnormalized fft
m_adFilter[i] /= m_nFilterPoints;
}
-
+
if (m_idFilterMethod == FILTER_METHOD_RFFTW) {
- m_realPlanForward = rfftw_create_plan (m_nFilterPoints, FFTW_REAL_TO_COMPLEX, FFTW_ESTIMATE);
- m_realPlanBackward = rfftw_create_plan (m_nOutputPoints, FFTW_COMPLEX_TO_REAL, FFTW_ESTIMATE);
- m_adRealFftInput = new fftw_real [ m_nFilterPoints ];
- m_adRealFftSignal = new fftw_real [ m_nOutputPoints ];
- for (i = 0; i < m_nFilterPoints; i++)
+ m_adRealFftInput = static_cast<double*>(fftw_malloc (sizeof(double) * m_nFilterPoints));
+ m_adRealFftOutput = static_cast<double*>(fftw_malloc (sizeof(double) * m_nFilterPoints));
+ m_realPlanForward = fftw_plan_r2r_1d (m_nFilterPoints, m_adRealFftInput, m_adRealFftOutput, FFTW_R2HC, FFTW_ESTIMATE);
+ m_adRealFftSignal = static_cast<double*>(fftw_malloc (sizeof(double) * m_nOutputPoints));
+ m_adRealFftBackwardOutput = static_cast<double*>(fftw_malloc (sizeof(double) * m_nOutputPoints));
+ m_realPlanBackward = fftw_plan_r2r_1d (m_nOutputPoints, m_adRealFftSignal, m_adRealFftBackwardOutput, FFTW_HC2R, FFTW_ESTIMATE);
+ for (i = 0; i < m_nFilterPoints; i++)
m_adRealFftInput[i] = 0;
} else if (m_idFilterMethod == FILTER_METHOD_FFTW) {
- m_complexPlanForward = fftw_create_plan (m_nFilterPoints, FFTW_FORWARD, FFTW_ESTIMATE);
- m_complexPlanBackward = fftw_create_plan (m_nOutputPoints, FFTW_BACKWARD, FFTW_ESTIMATE);
- m_adComplexFftInput = new fftw_complex [ m_nFilterPoints ];
- m_adComplexFftSignal = new fftw_complex [ m_nOutputPoints ];
- for (i = 0; i < m_nFilterPoints; i++)
- m_adComplexFftInput[i].re = m_adComplexFftInput[i].im = 0;
- for (i = 0; i < m_nOutputPoints; i++)
- m_adComplexFftSignal[i].re = m_adComplexFftSignal[i].im = 0;
+ m_adComplexFftInput = static_cast<fftw_complex*>(fftw_malloc (sizeof(fftw_complex) * m_nFilterPoints));
+ m_adComplexFftOutput = static_cast<fftw_complex*>(fftw_malloc (sizeof(fftw_complex) * m_nFilterPoints));
+ m_complexPlanForward = fftw_plan_dft_1d (m_nFilterPoints, m_adComplexFftInput, m_adComplexFftOutput, FFTW_FORWARD, FFTW_ESTIMATE);
+ m_adComplexFftSignal = static_cast<fftw_complex*>(fftw_malloc (sizeof(fftw_complex) * m_nOutputPoints));
+ m_adComplexFftBackwardOutput = static_cast<fftw_complex*>(fftw_malloc (sizeof(fftw_complex) * m_nOutputPoints));
+ m_complexPlanBackward = fftw_plan_dft_1d (m_nOutputPoints, m_adComplexFftSignal, m_adComplexFftBackwardOutput, FFTW_BACKWARD, FFTW_ESTIMATE);
+
+ for (i = 0; i < m_nFilterPoints; i++)
+ m_adComplexFftInput[i][0] = m_adComplexFftInput[i][1] = 0;
+ for (i = 0; i < m_nOutputPoints; i++)
+ m_adComplexFftSignal[i][0] = m_adComplexFftSignal[i][1] = 0;
}
#endif
-
+
}
ProcessSignal::~ProcessSignal (void)
delete [] m_adFourierSinTable;
delete [] m_adFourierCosTable;
delete [] m_adFilter;
-
+
#if HAVE_FFTW
if (m_idFilterMethod == FILTER_METHOD_FFTW) {
fftw_destroy_plan(m_complexPlanForward);
fftw_destroy_plan(m_complexPlanBackward);
- delete [] m_adComplexFftInput;
- delete [] m_adComplexFftSignal;
+ fftw_free (m_adComplexFftInput);
+ fftw_free (m_adComplexFftOutput);
+ fftw_free (m_adComplexFftSignal);
+ fftw_free (m_adComplexFftBackwardOutput);
}
if (m_idFilterMethod == FILTER_METHOD_RFFTW) {
- rfftw_destroy_plan(m_realPlanForward);
- rfftw_destroy_plan(m_realPlanBackward);
- delete [] m_adRealFftInput;
- delete [] m_adRealFftSignal;
+ fftw_destroy_plan(m_realPlanForward);
+ fftw_destroy_plan(m_realPlanBackward);
+ fftw_free (m_adRealFftInput);
+ fftw_free (m_adRealFftOutput);
+ fftw_free (m_adRealFftSignal);
+ fftw_free (m_adRealFftBackwardOutput);
}
#endif
}
ProcessSignal::convertFilterMethodNameToID (const char* const filterMethodName)
{
int fmID = FILTER_METHOD_INVALID;
-
+
for (int i = 0; i < s_iFilterMethodCount; i++)
if (strcasecmp (filterMethodName, s_aszFilterMethodName[i]) == 0) {
fmID = i;
break;
}
-
+
return (fmID);
}
ProcessSignal::convertFilterMethodIDToName (const int fmID)
{
static const char *name = "";
-
+
if (fmID >= 0 && fmID < s_iFilterMethodCount)
return (s_aszFilterMethodName [fmID]);
-
+
return (name);
}
ProcessSignal::convertFilterMethodIDToTitle (const int fmID)
{
static const char *title = "";
-
+
if (fmID >= 0 && fmID < s_iFilterMethodCount)
return (s_aszFilterMethodTitle [fmID]);
-
+
return (title);
}
ProcessSignal::convertFilterGenerationNameToID (const char* const fgName)
{
int fgID = FILTER_GENERATION_INVALID;
-
+
for (int i = 0; i < s_iFilterGenerationCount; i++)
if (strcasecmp (fgName, s_aszFilterGenerationName[i]) == 0) {
fgID = i;
break;
}
-
+
return (fgID);
}
ProcessSignal::convertFilterGenerationIDToName (const int fgID)
{
static const char *name = "";
-
+
if (fgID >= 0 && fgID < s_iFilterGenerationCount)
return (s_aszFilterGenerationName [fgID]);
-
+
return (name);
}
ProcessSignal::convertFilterGenerationIDToTitle (const int fgID)
{
static const char *name = "";
-
+
if (fgID >= 0 && fgID < s_iFilterGenerationCount)
return (s_aszFilterGenerationTitle [fgID]);
-
+
return (name);
}
ProcessSignal::filterSignal (const float constInput[], double output[]) const
{
double* input = new double [m_nSignalPoints];
- int i;\r
+ int i;
for (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);
int iDetFromCenter = i - (m_nSignalPoints / 2);
input[i] *= m_dFocalLength * cos (iDetFromCenter * m_dSignalInc);
}
- }\r
+ }
if (m_idFilterMethod == FILTER_METHOD_CONVOLUTION) {
for (i = 0; i < m_nSignalPoints; i++)
output[i] = convolve (input, m_dSignalInc, i, m_nSignalPoints);
for (i = m_nSignalPoints; i < m_nFilterPoints; i++)
inputSignal[i] = 0; // zeropad
std::complex<double>* fftSignal = new std::complex<double> [m_nFilterPoints];
- finiteFourierTransform (inputSignal, fftSignal, m_nFilterPoints, -1);\r
+ finiteFourierTransform (inputSignal, fftSignal, m_nFilterPoints, FORWARD);
delete inputSignal;
for (i = 0; i < m_nFilterPoints; i++)
fftSignal[i] *= m_adFilter[i];
double* inverseFourier = new double [m_nFilterPoints];
- finiteFourierTransform (fftSignal, inverseFourier, m_nFilterPoints, 1);\r
+ finiteFourierTransform (fftSignal, inverseFourier, m_nFilterPoints, BACKWARD);
delete fftSignal;
- for (i = 0; i < m_nSignalPoints; i++)
- output[i] = inverseFourier[i];\r
+ for (i = 0; i < m_nSignalPoints; i++)
+ output[i] = inverseFourier[i];
delete inverseFourier;
} else if (m_idFilterMethod == FILTER_METHOD_FOURIER_TABLE) {
double* inputSignal = new double [m_nFilterPoints];
for (i = m_nSignalPoints; i < m_nFilterPoints; i++)
inputSignal[i] = 0; // zeropad
std::complex<double>* fftSignal = new std::complex<double> [m_nFilterPoints];
- finiteFourierTransform (inputSignal, fftSignal, -1);\r
+ finiteFourierTransform (inputSignal, fftSignal, FORWARD);
delete inputSignal;
for (i = 0; i < m_nFilterPoints; i++)
fftSignal[i] *= m_adFilter[i];
double* inverseFourier = new double [m_nFilterPoints];
- finiteFourierTransform (fftSignal, inverseFourier, 1);\r
+ finiteFourierTransform (fftSignal, inverseFourier, BACKWARD);
delete fftSignal;
- for (i = 0; i < m_nSignalPoints; i++)
- output[i] = inverseFourier[i];\r
+ for (i = 0; i < m_nSignalPoints; i++)
+ output[i] = inverseFourier[i];
delete inverseFourier;
}
#if HAVE_FFTW
else if (m_idFilterMethod == FILTER_METHOD_RFFTW) {
for (i = 0; i < m_nSignalPoints; i++)
m_adRealFftInput[i] = input[i];
-
- fftw_real* fftOutput = new fftw_real [ m_nFilterPoints ];
- rfftw_one (m_realPlanForward, m_adRealFftInput, fftOutput);
+
+ fftw_execute (m_realPlanForward);
for (i = 0; i < m_nFilterPoints; i++)
- m_adRealFftSignal[i] = m_adFilter[i] * fftOutput[i];\r
- delete [] fftOutput;
+ m_adRealFftSignal[i] = m_adFilter[i] * m_adRealFftOutput[i];
for (i = m_nFilterPoints; i < m_nOutputPoints; i++)
- m_adRealFftSignal[i] = 0;
-
- fftw_real* ifftOutput = new fftw_real [ m_nOutputPoints ];
- rfftw_one (m_realPlanBackward, m_adRealFftSignal, ifftOutput);
+ m_adRealFftSignal[i] = 0;
+
+ fftw_execute (m_realPlanBackward);
for (i = 0; i < m_nSignalPoints * m_iPreinterpolationFactor; i++)
- output[i] = ifftOutput[i];\r
- delete [] ifftOutput;
+ output[i] = m_adRealFftBackwardOutput[i];
} else if (m_idFilterMethod == FILTER_METHOD_FFTW) {
for (i = 0; i < m_nSignalPoints; i++)
- m_adComplexFftInput[i].re = input[i];
-
- fftw_complex* fftOutput = new fftw_complex [ m_nFilterPoints ];
- fftw_one (m_complexPlanForward, m_adComplexFftInput, fftOutput);
+ m_adComplexFftInput[i][0] = input[i];
+
+ fftw_execute (m_complexPlanForward);
for (i = 0; i < m_nFilterPoints; i++) {
- m_adComplexFftSignal[i].re = m_adFilter[i] * fftOutput[i].re;
- m_adComplexFftSignal[i].im = m_adFilter[i] * fftOutput[i].im;
- }\r
- delete [] fftOutput;
- fftw_complex* ifftOutput = new fftw_complex [ m_nOutputPoints ];
- fftw_one (m_complexPlanBackward, m_adComplexFftSignal, ifftOutput);
- for (i = 0; i < m_nSignalPoints * m_iPreinterpolationFactor; i++)
- output[i] = ifftOutput[i].re;\r
- delete [] ifftOutput;
+ m_adComplexFftSignal[i][0] = m_adFilter[i] * m_adComplexFftOutput[i][0];
+ m_adComplexFftSignal[i][1] = m_adFilter[i] * m_adComplexFftOutput[i][1];
+ }
+ fftw_execute (m_complexPlanBackward);
+ for (i = 0; i < m_nSignalPoints * m_iPreinterpolationFactor; i++)
+ output[i] = m_adComplexFftBackwardOutput[i][0];
}
-#endif\r
+#endif
delete input;
}
/* NAME
-* convolve Discrete convolution of two functions
+* convolve Discrete convolution of two functions
*
* SYNOPSIS
* r = convolve (f1, f2, dx, n, np, func_type)
-* double r Convolved result
-* double f1[], f2[] Functions to be convolved
-* double dx Difference between successive x values
-* int n Array index to center convolution about
-* int np Number of points in f1 array
-* int func_type EVEN or ODD or EVEN_AND_ODD function f2
+* double r Convolved result
+* double f1[], f2[] Functions to be convolved
+* double dx Difference between successive x values
+* int n Array index to center convolution about
+* int np Number of points in f1 array
+* int func_type EVEN or ODD or EVEN_AND_ODD function f2
*
* NOTES
* f1 is the projection data, its indices range from 0 to np - 1.
* The index for f2, the filter, ranges from -(np-1) to (np-1).
* There are 3 ways to handle the negative vertices of f2:
-* 1. If we know f2 is an EVEN function, then f2[-n] = f2[n].
-* All filters used in reconstruction are even.
-* 2. If we know f2 is an ODD function, then f2[-n] = -f2[n]
+* 1. If we know f2 is an EVEN function, then f2[-n] = f2[n].
+* All filters used in reconstruction are even.
+* 2. If we know f2 is an ODD function, then f2[-n] = -f2[n]
* 3. If f2 is both ODD AND EVEN, then we must store the value of f2
-* for negative indices. Since f2 must range from -(np-1) to (np-1),
-* if we add (np - 1) to f2's array index, then f2's index will
-* range from 0 to 2 * (np - 1), and the origin, x = 0, will be
-* stored at f2[np-1].
+* for negative indices. Since f2 must range from -(np-1) to (np-1),
+* if we add (np - 1) to f2's array index, then f2's index will
+* range from 0 to 2 * (np - 1), and the origin, x = 0, will be
+* stored at f2[np-1].
*/
-double
+double
ProcessSignal::convolve (const double func[], const double dx, const int n, const int np) const
{
double sum = 0.0;
-
+
#if UNOPTIMIZED_CONVOLUTION
for (int i = 0; i < np; i++)
sum += func[i] * m_adFilter[n - i + (np - 1)];
for (int i = 0; i < np; i++)
sum += *func++ * *f2--;
#endif
-
+
return (sum * dx);
}
-double
+double
ProcessSignal::convolve (const float func[], const double dx, const int n, const int np) const
{
double sum = 0.0;
-
+
#if UNOPTIMIZED_CONVOLUTION
for (int i = 0; i < np; i++)
sum += func[i] * m_adFilter[n - i + (np - 1)];
for (int i = 0; i < np; i++)
sum += *func++ * *f2--;
#endif
-
+
return (sum * dx);
}
ProcessSignal::finiteFourierTransform (const double input[], double output[], const int n, int direction)
{
std::complex<double>* complexOutput = new std::complex<double> [n];
-
+
finiteFourierTransform (input, complexOutput, n, direction);
for (int i = 0; i < n; i++)
- output[i] = complexOutput[i].real();\r
+ output[i] = complexOutput[i].real();
delete [] complexOutput;
}
{
if (direction < 0)
direction = -1;
- else
+ else
direction = 1;
-
+
double angleIncrement = direction * 2 * PI / n;
for (int i = 0; i < n; i++) {
double sumReal = 0;
{
if (direction < 0)
direction = -1;
- else
+ else
direction = 1;
-
+
double angleIncrement = direction * 2 * PI / n;
for (int i = 0; i < n; i++) {
std::complex<double> sum (0,0);
{
if (direction < 0)
direction = -1;
- else
+ else
direction = 1;
-
+
double angleIncrement = direction * 2 * PI / n;
for (int i = 0; i < n; i++) {
double sumReal = 0;
{
if (direction < 0)
direction = -1;
- else
+ else
direction = 1;
-
+
for (int i = 0; i < m_nFilterPoints; i++) {
double sumReal = 0, sumImag = 0;
for (int j = 0; j < m_nFilterPoints; j++) {
{
if (direction < 0)
direction = -1;
- else
+ else
direction = 1;
-
+
for (int i = 0; i < m_nFilterPoints; i++) {
double sumReal = 0, sumImag = 0;
for (int j = 0; j < m_nFilterPoints; j++) {
int tableIndex = i * j;
if (direction > 0) {
- sumReal += input[j].real() * m_adFourierCosTable[tableIndex]
+ sumReal += input[j].real() * m_adFourierCosTable[tableIndex]
- input[j].imag() * m_adFourierSinTable[tableIndex];
sumImag += input[j].real() * m_adFourierSinTable[tableIndex]
+ input[j].imag() * m_adFourierCosTable[tableIndex];
} else {
- sumReal += input[j].real() * m_adFourierCosTable[tableIndex]
+ sumReal += input[j].real() * m_adFourierCosTable[tableIndex]
- input[j].imag() * -m_adFourierSinTable[tableIndex];
sumImag += input[j].real() * -m_adFourierSinTable[tableIndex]
+ input[j].imag() * m_adFourierCosTable[tableIndex];
{
if (direction < 0)
direction = -1;
- else
+ else
direction = 1;
-
+
for (int i = 0; i < m_nFilterPoints; i++) {
double sumReal = 0;
for (int j = 0; j < m_nFilterPoints; j++) {
int tableIndex = i * j;
if (direction > 0) {
- sumReal += input[j].real() * m_adFourierCosTable[tableIndex]
+ sumReal += input[j].real() * m_adFourierCosTable[tableIndex]
- input[j].imag() * m_adFourierSinTable[tableIndex];
} else {
- sumReal += input[j].real() * m_adFourierCosTable[tableIndex]
+ sumReal += input[j].real() * m_adFourierCosTable[tableIndex]
- input[j].imag() * -m_adFourierSinTable[tableIndex];
}
}
}
}
-// Odd Number of Points
-// Natural Frequency Order: -(n-1)/2...-1,0,1...(n-1)/2
-// Fourier Frequency Order: 0, 1..(n-1)/2,-(n-1)/2...-1
-// Even Number of Points
-// Natural Frequency Order: -n/2...-1,0,1...((n/2)-1)
-// Fourier Frequency Order: 0,1...((n/2)-1),-n/2...-1
-
-void\r
-ProcessSignal::shuffleNaturalToFourierOrder (double* pdVector, const int n)\r
-{\r
- double* pdTemp = new double [n];\r
- int i;\r
- if (n % 2) { // Odd\r
- int iHalfN = (n - 1) / 2;\r
- \r
- pdTemp[0] = pdVector[iHalfN];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i + 1] = pdVector[i + 1 + iHalfN];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i + iHalfN + 1] = pdVector[i];\r
- } else { // Even\r
- int iHalfN = n / 2;\r
- pdTemp[0] = pdVector[iHalfN];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i + 1] = pdVector[i + iHalfN];\r
- for (i = 0; i < iHalfN - 1; i++)\r
- pdTemp[i + iHalfN + 1] = pdVector[i];\r
- }\r
- \r
- for (i = 0; i < n; i++)\r
- pdVector[i] = pdTemp[i];\r
- delete pdTemp;\r
-}\r
-\r
-void\r
-ProcessSignal::shuffleNaturalToFourierOrder (std::complex<double>* pdVector, const int n)\r
-{\r
- std::complex<double>* pdTemp = new std::complex<double> [n];\r
- int i;\r
- if (n % 2) { // Odd\r
- int iHalfN = (n - 1) / 2;\r
- \r
- pdTemp[0] = pdVector[iHalfN];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i + 1] = pdVector[i + 1 + iHalfN];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i + iHalfN + 1] = pdVector[i];\r
- } else { // Even\r
- int iHalfN = n / 2;\r
- pdTemp[0] = pdVector[iHalfN];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i + 1] = pdVector[i + iHalfN];\r
- for (i = 0; i < iHalfN - 1; i++)\r
- pdTemp[i + iHalfN + 1] = pdVector[i];\r
- }\r
- \r
- for (i = 0; i < n; i++)\r
- pdVector[i] = pdTemp[i];\r
- delete [] pdTemp;\r
-}\r
-\r
-
-void\r
-ProcessSignal::shuffleFourierToNaturalOrder (double* pdVector, const int n)\r
-{\r
- double* pdTemp = new double [n];\r
- int i;\r
- if (n % 2) { // Odd\r
- int iHalfN = (n - 1) / 2;\r
- \r
- pdTemp[iHalfN] = pdVector[0];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i + 1 + iHalfN] = pdVector[i + 1];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i] = pdVector[i + iHalfN + 1];\r
- } else { // Even\r
- int iHalfN = n / 2;\r
- pdTemp[iHalfN] = pdVector[0];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i] = pdVector[i + iHalfN];\r
- for (i = 0; i < iHalfN - 1; i++)\r
- pdTemp[i + iHalfN + 1] = pdVector[i+1];\r
- }\r
- \r
- for (i = 0; i < n; i++)\r
- pdVector[i] = pdTemp[i];\r
- delete pdTemp;\r
-}\r
-\r
-void\r
-ProcessSignal::shuffleFourierToNaturalOrder (std::complex<double>* pdVector, const int n)\r
-{\r
- std::complex<double>* pdTemp = new std::complex<double> [n];\r
- int i;\r
- if (n % 2) { // Odd\r
- int iHalfN = (n - 1) / 2;\r
- \r
- pdTemp[iHalfN] = pdVector[0];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i + 1 + iHalfN] = pdVector[i + 1];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i] = pdVector[i + iHalfN + 1];\r
- } else { // Even\r
- int iHalfN = n / 2;\r
- pdTemp[iHalfN] = pdVector[0];\r
- for (i = 0; i < iHalfN; i++)\r
- pdTemp[i] = pdVector[i + iHalfN];\r
- for (i = 0; i < iHalfN - 1; i++)\r
- pdTemp[i + iHalfN + 1] = pdVector[i+1];\r
- }\r
- \r
- for (i = 0; i < n; i++)\r
- pdVector[i] = pdTemp[i];\r
- delete [] pdTemp;\r
-}\r
-\r
+
+int
+ProcessSignal::addZeropadFactor (int n, int iZeropad)
+{
+ if (iZeropad > 0) {
+ double dLogBase2 = log(n) / log(2);
+ int iLogBase2 = static_cast<int>(floor (dLogBase2));
+ int iPaddedN = 1 << (iLogBase2 + iZeropad);
+#ifdef DEBUG
+ sys_error (ERR_TRACE, "Zeropadding %d to %d", n, iPaddedN);
+#endif
+ return iPaddedN;
+ }
+
+ return n;
+}