** This is part of the CTSim program
** Copyright (C) 1983-2000 Kevin Rosenberg
**
-** $Id: filter.cpp,v 1.23 2000/07/31 14:48:35 kevin Exp $
+** $Id: filter.cpp,v 1.28 2000/11/10 15:29:37 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 int SignalFilter::FILTER_INVALID = -1 ;
const int SignalFilter::FILTER_ABS_BANDLIMIT = 0; // filter times |x = |
-const int SignalFilter::FILTER_ABS_SINC = 1;
-const int SignalFilter::FILTER_ABS_G_HAMMING = 2;
-const int SignalFilter::FILTER_ABS_COSINE = 3;
+const int SignalFilter::FILTER_ABS_G_HAMMING = 1;
+const int SignalFilter::FILTER_ABS_COSINE = 2;
+const int SignalFilter::FILTER_ABS_SINC = 3;
const int SignalFilter::FILTER_SHEPP = 4;
const int SignalFilter::FILTER_BANDLIMIT = 5;
const int SignalFilter::FILTER_SINC = 6;
const char* SignalFilter::s_aszFilterName[] = {
{"abs_bandlimit"},
- {"abs_sinc"},
{"abs_hamming"},
{"abs_cosine"},
+ {"abs_sinc"},
{"shepp"},
{"bandlimit"},
{"sinc"},
const char* SignalFilter::s_aszFilterTitle[] = {
{"Abs(w) * Bandlimit"},
- {"Abs(w) * Sinc"},
{"Abs(w) * Hamming"},
{"Abs(w) * Cosine"},
+ {"Abs(w) * Sinc"},
{"Shepp"},
{"Bandlimit"},
{"Sinc"},
const int SignalFilter::s_iFilterCount = sizeof(s_aszFilterName) / sizeof(const char*);
-const int SignalFilter::FILTER_METHOD_INVALID = -1;
-const int SignalFilter::FILTER_METHOD_CONVOLUTION = 0;
-const int SignalFilter::FILTER_METHOD_FOURIER = 1;
-const int SignalFilter::FILTER_METHOD_FOURIER_TABLE = 2;
-const int SignalFilter::FILTER_METHOD_FFT = 3;
-#if HAVE_FFTW
-const int SignalFilter::FILTER_METHOD_FFTW = 4;
-const int SignalFilter::FILTER_METHOD_RFFTW =5 ;
-#endif
-
-const char* SignalFilter::s_aszFilterMethodName[] = {
- {"convolution"},
- {"fourier"},
- {"fouier_table"},
- {"fft"},
-#if HAVE_FFTW
- {"fftw"},
- {"rfftw"},
-#endif
-};
-
-const char* SignalFilter::s_aszFilterMethodTitle[] = {
- {"Convolution"},
- {"Direct Fourier"},
- {"Fouier Trigometric Table Lookout"},
- {"FFT"},
-#if HAVE_FFTW
- {"FFTW"},
- {"Real/Half-Complex FFTW"},
-#endif
-};
-
-const int SignalFilter::s_iFilterMethodCount = sizeof(s_aszFilterMethodName) / sizeof(const char*);
-
const int SignalFilter::DOMAIN_INVALID = -1;
const int SignalFilter::DOMAIN_FREQUENCY = 0;
* int filt_type Type of filter wanted
* double bw Bandwidth of filter
* double filterMin, filterMax Filter limits
- * int nSignalPoints Number of points in signal
+ * int nFilterPoints Number of points in signal
* double param General input parameter to filters
* int domain FREQUENCY or SPATIAL domain wanted
*/
-SignalFilter::SignalFilter (const char* filterName, const char* filterMethodName, double bw, double signalIncrement, int nSignalPoints, double param, const char* domainName, int zeropad = 0, int preinterpolationFactor = 1)
- : m_vecFilter(NULL), m_vecFourierCosTable(NULL), m_vecFourierSinTable(NULL), m_fail(false)
+SignalFilter::SignalFilter (const char* szFilterName, double dFilterMinimum, double dFilterMaximum, int nFilterPoints, double dBandwidth, double dFilterParam, const char* szDomainName)
+ : m_adFilter(NULL), m_fail(false)
{
- m_idFilter = convertFilterNameToID (filterName);
+ m_idFilter = convertFilterNameToID (szFilterName);
if (m_idFilter == FILTER_INVALID) {
m_fail = true;
m_failMessage = "Invalid Filter name ";
- m_failMessage += filterName;
+ m_failMessage += szFilterName;
return;
}
- m_idFilterMethod = convertFilterMethodNameToID (filterMethodName);
- if (m_idFilterMethod == FILTER_METHOD_INVALID) {
- m_fail = true;
- m_failMessage = "Invalid filter method name ";
- m_failMessage += filterMethodName;
- return;
- }
- m_idDomain = convertDomainNameToID (domainName);
+ m_idDomain = convertDomainNameToID (szDomainName);
if (m_idDomain == DOMAIN_INVALID) {
m_fail = true;
m_failMessage = "Invalid domain name ";
- m_failMessage += domainName;
+ m_failMessage += szDomainName;
return;
}
- init (m_idFilter, m_idFilterMethod, bw, signalIncrement, nSignalPoints, param, m_idDomain, zeropad, preinterpolationFactor);
+ init (m_idFilter, dFilterMinimum, dFilterMaximum, nFilterPoints, dBandwidth, dFilterParam, m_idDomain);
}
-SignalFilter::SignalFilter (const int filterID, const int filterMethodID, double bw, double signalIncrement, int nSignalPoints, double param, const int domainID, int zeropad = 0, int preinterpolationFactor = 1)
- : m_vecFilter(NULL), m_vecFourierCosTable(NULL), m_vecFourierSinTable(NULL), m_fail(false)
+SignalFilter::SignalFilter (const int idFilter, double dFilterMinimum, double dFilterMaximum, int nFilterPoints, double dBandwidth, double dFilterParam, const int idDomain)
+ : m_adFilter(NULL), m_fail(false)
{
- init (filterID, filterMethodID, bw, signalIncrement, nSignalPoints, param, domainID, zeropad, preinterpolationFactor);
+ init (idFilter, dFilterMinimum, dFilterMaximum, nFilterPoints, dBandwidth, dFilterParam, idDomain);
}
-SignalFilter::SignalFilter (const char* filterName, const char* domainName, double bw, double param)
- : m_vecFilter(NULL), m_vecFourierCosTable(NULL), m_vecFourierSinTable(NULL), m_fail(false)
+SignalFilter::SignalFilter (const char* szFilterName, const char* szDomainName, double dBandwidth, double dFilterParam)
+ : m_adFilter(NULL), m_fail(false)
{
- m_bw = bw;
- m_nSignalPoints = 0;
m_nFilterPoints = 0;
- m_filterParam = param;
- m_idFilter = convertFilterNameToID (filterName);
+ m_dBandwidth = dBandwidth;
+ m_dFilterParam = dFilterParam;
+ m_idFilter = convertFilterNameToID (szFilterName);
if (m_idFilter == FILTER_INVALID) {
m_fail = true;
m_failMessage = "Invalid Filter name ";
- m_failMessage += filterName;
+ m_failMessage += szFilterName;
return;
}
- m_idDomain = convertDomainNameToID (domainName);
+ m_idDomain = convertDomainNameToID (szDomainName);
if (m_idDomain == DOMAIN_INVALID) {
m_fail = true;
m_failMessage = "Invalid domain name ";
- m_failMessage += domainName;
+ m_failMessage += szDomainName;
return;
}
}
void
-SignalFilter::init (const int filterID, const int filterMethodID, double bw, double signalIncrement, int nSignalPoints, double filterParam, const int domainID, int zeropad, int preinterpolationFactor)
+SignalFilter::init (const int idFilter, double dFilterMinimum, double dFilterMaximum, int nFilterPoints, double dBandwidth, double dFilterParam, const int idDomain)
{
- m_bw = bw;
- m_idFilter = filterID;
- m_idDomain = domainID;
- m_idFilterMethod = filterMethodID;
- if (m_idFilter == FILTER_INVALID || m_idDomain == DOMAIN_INVALID || m_idFilterMethod == FILTER_METHOD_INVALID) {
+ m_idFilter = idFilter;
+ m_idDomain = idDomain;
+ if (m_idFilter == FILTER_INVALID || m_idDomain == DOMAIN_INVALID) {
m_fail = true;
return;
}
- m_traceLevel = TRACE_NONE;
- m_nameFilter = convertFilterIDToName (m_idFilter);
- m_nameDomain = convertDomainIDToName (m_idDomain);
- m_nameFilterMethod = convertFilterMethodIDToName (m_idFilterMethod);
- m_nSignalPoints = nSignalPoints;
- m_signalInc = signalIncrement;
- m_filterParam = filterParam;
- m_zeropad = zeropad;
- m_preinterpolationFactor = preinterpolationFactor;
-
- m_vecFourierCosTable = NULL;
- m_vecFourierSinTable = NULL;
- m_vecFilter = NULL;
-
- if (m_idFilterMethod == FILTER_METHOD_FFT) {
-#if HAVE_FFTW
- m_idFilterMethod = FILTER_METHOD_RFFTW;
-#else
+ if (nFilterPoints < 2) {
m_fail = true;
- m_failMessage = "FFT not yet implemented";
+ m_failMessage = "Number of filter points ";
+ m_failMessage += nFilterPoints;
+ m_failMessage = " less than 2";
return;
-#endif
}
- if (m_idFilterMethod == FILTER_METHOD_FOURIER || m_idFilterMethod == FILTER_METHOD_FOURIER_TABLE || m_idFilterMethod == FILTER_METHOD_FFT
-#if HAVE_FFTW
- || m_idFilterMethod == FILTER_METHOD_FFTW || m_idFilterMethod == FILTER_METHOD_RFFTW
-#endif
- ) {
- m_nFilterPoints = m_nSignalPoints;
- if (m_zeropad > 0) {
- double logBase2 = log(m_nSignalPoints) / log(2);
- int nextPowerOf2 = static_cast<int>(floor(logBase2));
- if (logBase2 != floor(logBase2))
- nextPowerOf2++;
- nextPowerOf2 += (m_zeropad - 1);
- m_nFilterPoints = 1 << nextPowerOf2;
- if (m_traceLevel >= TRACE_TEXT)
- cout << "nFilterPoints = " << m_nFilterPoints << endl;
- }
- m_nOutputPoints = m_nFilterPoints * m_preinterpolationFactor;
- m_filterMin = -1. / (2 * m_signalInc);
- m_filterMax = 1. / (2 * m_signalInc);
- m_filterInc = (m_filterMax - m_filterMin) / m_nFilterPoints;
- m_vecFilter = new double [m_nFilterPoints];
- int halfFilter = m_nFilterPoints / 2;
- for (int i = 0; i <= halfFilter; i++)
- m_vecFilter[i] = static_cast<double>(i) / halfFilter/ (2. * m_signalInc);
- for (int i = 1; i <= halfFilter; i++)
- m_vecFilter[m_nFilterPoints - i] = static_cast<double>(i) / halfFilter / (2. * m_signalInc);
- }
-
- // 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;
- double angleIncrement = (2. * PI) / m_nFilterPoints;
- m_vecFourierCosTable = new double[ nFourier ];
- m_vecFourierSinTable = new double[ nFourier ];
- double angle = 0;
- for (int i = 0; i < nFourier; i++) {
- m_vecFourierCosTable[i] = cos (angle);
- m_vecFourierSinTable[i] = sin (angle);
- angle += angleIncrement;
- }
- }
+ m_nameFilter = convertFilterIDToName (m_idFilter);
+ m_nameDomain = convertDomainIDToName (m_idDomain);
+ m_nFilterPoints = nFilterPoints;
+ m_dFilterParam = dFilterParam;
+ m_dBandwidth = dBandwidth;
+ m_dFilterMin = dFilterMinimum;
+ m_dFilterMax = dFilterMaximum;
-#if HAVE_FFTW
- if (m_idFilterMethod == FILTER_METHOD_FFTW || m_idFilterMethod == FILTER_METHOD_RFFTW) {
- for (int i = 0; i < m_nFilterPoints; i++) //fftw uses unnormalized fft
- m_vecFilter[i] /= m_nFilterPoints;
- }
+ m_dFilterInc = (m_dFilterMax - m_dFilterMin) / (m_nFilterPoints - 1);
+ m_adFilter = new double [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_vecRealFftInput = new fftw_real [ m_nFilterPoints ];
- m_vecRealFftSignal = new fftw_real [ m_nOutputPoints ];
- for (int i = 0; i < m_nFilterPoints; i++)
- m_vecRealFftInput[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_vecComplexFftInput = new fftw_complex [ m_nFilterPoints ];
- m_vecComplexFftSignal = new fftw_complex [ m_nOutputPoints ];
- for (int i = 0; i < m_nFilterPoints; i++)
- m_vecComplexFftInput[i].re = m_vecComplexFftInput[i].im = 0;
- for (int i = 0; i < m_nOutputPoints; i++)
- m_vecComplexFftSignal[i].re = m_vecComplexFftSignal[i].im = 0;
- }
-#endif
-
- if (m_idFilterMethod == FILTER_METHOD_CONVOLUTION) {
- m_nFilterPoints = 2 * m_nSignalPoints - 1;
- m_filterMin = -m_signalInc * (m_nSignalPoints - 1);
- m_filterMax = m_signalInc * (m_nSignalPoints - 1);
- m_filterInc = (m_filterMax - m_filterMin) / (m_nFilterPoints - 1);
- m_vecFilter = new double[ m_nFilterPoints ];
-
- if (m_idFilter == FILTER_SHEPP) {
- double a = 2 * m_bw;
- double c = - 4. / (a * a);
- int center = (m_nFilterPoints - 1) / 2;
- int sidelen = center;
- m_vecFilter[center] = 4. / (a * a);
-
- for (int i = 1; i <= sidelen; i++ )
- m_vecFilter [center + i] = m_vecFilter [center - i] = c / (4 * (i * i) - 1);
- } else if (m_idDomain == DOMAIN_FREQUENCY) {
- double x;
- int i;
- for (x = m_filterMin, i = 0; i < m_nFilterPoints; x += m_filterInc, i++)
- m_vecFilter[i] = frequencyResponse (x, m_filterParam);
- } else if (m_idDomain == DOMAIN_SPATIAL) {
- double x;
- int i;
- for (x = m_filterMin, i = 0; i < m_nFilterPoints; x += m_filterInc, i++) {
- if (haveAnalyticSpatial(m_idFilter))
- m_vecFilter[i] = spatialResponseAnalytic (x, m_filterParam);
- else
- m_vecFilter[i] = spatialResponseCalc (x, m_filterParam);
-#if LIMIT_BANDWIDTH_TRIAL
- if (i < m_nFilterPoints / 4 || i > (m_nFilterPoints * 3) / 4)
- m_vecFilter[i] = 0;
-#endif
- }
- } else {
- m_failMessage = "Illegal domain name ";
- m_failMessage += m_idDomain;
- m_fail = true;
- }
- }
+ if (m_idDomain == DOMAIN_FREQUENCY)
+ createFrequencyFilter (m_adFilter);
+ else if (m_idDomain == DOMAIN_SPATIAL)
+ createSpatialFilter (m_adFilter);
}
+
SignalFilter::~SignalFilter (void)
{
- delete [] m_vecFilter;
- delete [] m_vecFourierSinTable;
- delete [] m_vecFourierCosTable;
-
-#if HAVE_FFTW
- if (m_idFilterMethod == FILTER_METHOD_FFTW) {
- fftw_destroy_plan(m_complexPlanForward);
- fftw_destroy_plan(m_complexPlanBackward);
- delete [] m_vecComplexFftInput;
- delete [] m_vecComplexFftSignal;
- }
- if (m_idFilterMethod == FILTER_METHOD_RFFTW) {
- rfftw_destroy_plan(m_realPlanForward);
- rfftw_destroy_plan(m_realPlanBackward);
- delete [] m_vecRealFftInput;
- delete [] m_vecRealFftSignal;
- }
-#endif
+ delete [] m_adFilter;
}
+void
+SignalFilter::createFrequencyFilter (double* adFilter) const
+{
+ double x;
+ int i;
+ for (x = m_dFilterMin, i = 0; i < m_nFilterPoints; x += m_dFilterInc, i++)
+ adFilter[i] = frequencyResponse (x);
+}
+
+
+void
+SignalFilter::createSpatialFilter (double* adFilter) const
+{
+ if (m_idFilter == FILTER_SHEPP) {
+ double a = 2 * m_dBandwidth;
+ double c = - 4. / (a * a);
+ int center = (m_nFilterPoints - 1) / 2;
+ int sidelen = center;
+ m_adFilter[center] = 4. / (a * a);
+
+ for (int i = 1; i <= sidelen; i++ )
+ m_adFilter [center + i] = m_adFilter [center - i] = c / (4 * (i * i) - 1);
+ } else {
+ double x = m_dFilterMin;
+ for (int i = 0; i < m_nFilterPoints; i++, x += m_dFilterInc) {
+ if (haveAnalyticSpatial(m_idFilter))
+ m_adFilter[i] = spatialResponseAnalytic (x);
+ else
+ m_adFilter[i] = spatialResponseCalc (x);
+ }
+ }
+}
int
SignalFilter::convertFilterNameToID (const char *filterName)
int filterID = FILTER_INVALID;
for (int i = 0; i < s_iFilterCount; i++)
- if (strcasecmp (filterName, s_aszFilterName[i]) == 0) {
+cc if (strcasecmp (filterName, s_aszFilterName[i]) == 0) {
filterID = i;
break;
}
return (title);
}
-int
-SignalFilter::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);
-}
-
-const char *
-SignalFilter::convertFilterMethodIDToName (const int fmID)
-{
- static const char *name = "";
-
- if (fmID >= 0 && fmID < s_iFilterMethodCount)
- return (s_aszFilterMethodName [fmID]);
-
- return (name);
-}
-
-const char *
-SignalFilter::convertFilterMethodIDToTitle (const int fmID)
-{
- static const char *title = "";
-
- if (fmID >= 0 && fmID < s_iFilterMethodCount)
- return (s_aszFilterTitle [fmID]);
-
- return (title);
-}
-
int
SignalFilter::convertDomainNameToID (const char* const domainName)
{
return (title);
}
-void
-SignalFilter::filterSignal (const float input[], double output[]) const
-{
- if (m_idFilterMethod == FILTER_METHOD_CONVOLUTION) {
- for (int i = 0; i < m_nSignalPoints; i++)
- output[i] = convolve (input, m_signalInc, i, m_nSignalPoints);
- } else if (m_idFilterMethod == FILTER_METHOD_FOURIER) {
- double inputSignal[m_nFilterPoints];
- for (int i = 0; i < m_nSignalPoints; i++)
- inputSignal[i] = input[i];
- for (int i = m_nSignalPoints; i < m_nFilterPoints; i++)
- inputSignal[i] = 0; // zeropad
- complex<double> fftSignal[m_nFilterPoints];
- finiteFourierTransform (inputSignal, fftSignal, m_nFilterPoints, -1);
- for (int i = 0; i < m_nFilterPoints; i++)
- fftSignal[i] *= m_vecFilter[i];
- double inverseFourier[m_nFilterPoints];
- finiteFourierTransform (fftSignal, inverseFourier, m_nFilterPoints, 1);
- for (int i = 0; i < m_nSignalPoints; i++)
- output[i] = inverseFourier[i];
- } else if (m_idFilterMethod == FILTER_METHOD_FOURIER_TABLE) {
- double inputSignal[m_nFilterPoints];
- for (int i = 0; i < m_nSignalPoints; i++)
- inputSignal[i] = input[i];
- for (int i = m_nSignalPoints; i < m_nFilterPoints; i++)
- inputSignal[i] = 0; // zeropad
- complex<double> fftSignal[m_nFilterPoints];
- finiteFourierTransform (inputSignal, fftSignal, -1);
- for (int i = 0; i < m_nFilterPoints; i++)
- fftSignal[i] *= m_vecFilter[i];
- double inverseFourier[m_nFilterPoints];
- finiteFourierTransform (fftSignal, inverseFourier, 1);
- for (int i = 0; i < m_nSignalPoints; i++)
- output[i] = inverseFourier[i];
- }
-#if HAVE_FFTW
- else if (m_idFilterMethod == FILTER_METHOD_RFFTW) {
- for (int i = 0; i < m_nSignalPoints; i++)
- m_vecRealFftInput[i] = input[i];
-
- fftw_real fftOutput [ m_nFilterPoints ];
- rfftw_one (m_realPlanForward, m_vecRealFftInput, fftOutput);
- for (int i = 0; i < m_nFilterPoints; i++)
- m_vecRealFftSignal[i] = m_vecFilter[i] * fftOutput[i];
- for (int i = m_nFilterPoints; i < m_nOutputPoints; i++)
- m_vecRealFftSignal[i] = 0;
-
- fftw_real ifftOutput [ m_nOutputPoints ];
- rfftw_one(m_realPlanBackward, m_vecRealFftSignal, ifftOutput);
- for (int i = 0; i < m_nSignalPoints * m_preinterpolationFactor; i++)
- output[i] = ifftOutput[i];
- } else if (m_idFilterMethod == FILTER_METHOD_FFTW) {
- for (int i = 0; i < m_nSignalPoints; i++)
- m_vecComplexFftInput[i].re = input[i];
-
- fftw_complex fftOutput [ m_nFilterPoints ];
- fftw_one(m_complexPlanForward, m_vecComplexFftInput, fftOutput);
- for (int i = 0; i < m_nFilterPoints; i++) {
- m_vecComplexFftSignal[i].re = m_vecFilter[i] * fftOutput[i].re;
- m_vecComplexFftSignal[i].im = m_vecFilter[i] * fftOutput[i].im;
- }
- fftw_complex ifftOutput [ m_nOutputPoints ];
- fftw_one(m_complexPlanBackward, m_vecComplexFftSignal, ifftOutput);
- for (int i = 0; i < m_nSignalPoints * m_preinterpolationFactor; i++)
- output[i] = ifftOutput[i].re;
- }
-#endif
-}
double
SignalFilter::response (double x)
double response = 0;
if (m_idDomain == DOMAIN_SPATIAL)
- response = spatialResponse (m_idFilter, m_bw, x, m_filterParam);
+ response = spatialResponse (m_idFilter, m_dBandwidth, x, m_dFilterParam);
else if (m_idDomain == DOMAIN_FREQUENCY)
- response = frequencyResponse (m_idFilter, m_bw, x, m_filterParam);
+ response = frequencyResponse (m_idFilter, m_dBandwidth, x, m_dFilterParam);
return (response);
}
return spatialResponseCalc (filterID, bw, x, param, N_INTEGRAL);
}
+void
+SignalFilter::copyFilterData (double* pdFilter, const int iStart, const int nPoints) const
+{
+ int iFirst = clamp (iStart, 0, m_nFilterPoints - 1);
+ int iLast = clamp (iFirst + nPoints - 1, 0, m_nFilterPoints - 1);
+
+ for (int i = iFirst; i <= iLast; i++)
+ pdFilter[i - iFirst] = m_adFilter[i];
+}
+
/* NAME
* filter_spatial_response_calc Calculate filter by discrete inverse fourier
* transform of filters's frequency
*/
double
-SignalFilter::spatialResponseCalc (double x, double param) const
+SignalFilter::spatialResponseCalc (double x) const
{
- return (spatialResponseCalc (m_idFilter, m_bw, x, param, N_INTEGRAL));
+ return (spatialResponseCalc (m_idFilter, m_dBandwidth, x, m_dFilterParam, N_INTEGRAL));
}
double
*/
double
-SignalFilter::frequencyResponse (double u, double param) const
+SignalFilter::frequencyResponse (double u) const
{
- return frequencyResponse (m_idFilter, m_bw, u, param);
+ return frequencyResponse (m_idFilter, m_dBandwidth, u, m_dFilterParam);
}
switch (filterID) {
case FILTER_BANDLIMIT:
- if (au >= bw / 2)
+ if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
q = 0.;
else
q = 1;
break;
case FILTER_ABS_BANDLIMIT:
- if (au >= bw / 2)
+ if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
q = 0.;
else
q = au;
break;
case FILTER_TRIANGLE:
- if (au >= bw)
+ if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
q = 0;
else
q = 1 - au / bw;
break;
case FILTER_COSINE:
- if (au >= bw / 2)
+ if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
q = 0;
else
q = cos(PI * u / bw);
break;
case FILTER_ABS_COSINE:
- if (au >= bw / 2)
+ if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
q = 0;
else
q = au * cos(PI * u / bw);
q = au * bw * sinc (PI * bw * u, 1.);
break;
case FILTER_G_HAMMING:
- if (au >= bw / 2)
+ if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
q = 0;
else
q = param + (1 - param) * cos (TWOPI * u / bw);
break;
case FILTER_ABS_G_HAMMING:
- if (au >= bw / 2)
+ if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
q = 0;
else
q = au * (param + (1 - param) * cos(TWOPI * u / bw));
*/
double
-SignalFilter::spatialResponseAnalytic (double x, double param) const
+SignalFilter::spatialResponseAnalytic (double x) const
{
- return spatialResponseAnalytic (m_idFilter, m_bw, x, param);
+ return spatialResponseAnalytic (m_idFilter, m_dBandwidth, x, m_dFilterParam);
}
const bool
* Returns the value of integral of u*cos(u)*dV for V = 0 to w
*/
-double
-SignalFilter::integral_abscos (double u, double w)
-{
- return (fabs (u) > F_EPSILON
- ? (cos(u * w) - 1) / (u * u) + w / u * sin (u * w)
- : (w * w / 2));
-}
-
-
-/* NAME
- * 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
- *
- * 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]
- * 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].
- */
-
-double
-SignalFilter::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_vecFilter[n - i + (np - 1)];
-#else
- double* f2 = m_vecFilter + n + (np - 1);
- for (int i = 0; i < np; i++)
- sum += *func++ * *f2--;
-#endif
-
- return (sum * dx);
-}
-
-
-double
-SignalFilter::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_vecFilter[n - i + (np - 1)];
-#else
-double* f2 = m_vecFilter + n + (np - 1);
-for (int i = 0; i < np; i++)
- sum += *func++ * *f2--;
-#endif
-
- return (sum * dx);
-}
-
-
-void
-SignalFilter::finiteFourierTransform (const double input[], complex<double> output[], const int n, int direction)
-{
- if (direction < 0)
- direction = -1;
- else
- direction = 1;
-
- double angleIncrement = direction * 2 * PI / n;
- for (int i = 0; i < n; i++) {
- double sumReal = 0;
- double sumImag = 0;
- for (int j = 0; j < n; j++) {
- double angle = i * j * angleIncrement;
- sumReal += input[j] * cos(angle);
- sumImag += input[j] * sin(angle);
- }
- if (direction < 0) {
- sumReal /= n;
- sumImag /= n;
- }
- output[i] = complex<double> (sumReal, sumImag);
- }
-}
-
-
-void
-SignalFilter::finiteFourierTransform (const complex<double> input[], complex<double> output[], const int n, int direction)
-{
- if (direction < 0)
- direction = -1;
- else
- direction = 1;
-
- double angleIncrement = direction * 2 * PI / n;
- for (int i = 0; i < n; i++) {
- complex<double> sum (0,0);
- for (int j = 0; j < n; j++) {
- double angle = i * j * angleIncrement;
- complex<double> exponentTerm (cos(angle), sin(angle));
- sum += input[j] * exponentTerm;
- }
- if (direction < 0) {
- sum /= n;
- }
- output[i] = sum;
- }
-}
-
-void
-SignalFilter::finiteFourierTransform (const complex<double> input[], double output[], const int n, int direction)
-{
- if (direction < 0)
- direction = -1;
- else
- direction = 1;
-
- double angleIncrement = direction * 2 * PI / n;
- for (int i = 0; i < n; i++) {
- double sumReal = 0;
- for (int j = 0; j < n; j++) {
- double angle = i * j * angleIncrement;
- sumReal += input[j].real() * cos(angle) - input[j].imag() * sin(angle);
- }
- if (direction < 0) {
- sumReal /= n;
- }
- output[i] = sumReal;
- }
-}
-
-void
-SignalFilter::finiteFourierTransform (const double input[], complex<double> output[], int direction) const
-{
- if (direction < 0)
- direction = -1;
- 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] * m_vecFourierCosTable[tableIndex];
- sumImag += input[j] * m_vecFourierSinTable[tableIndex];
- } else {
- sumReal += input[j] * m_vecFourierCosTable[tableIndex];
- sumImag -= input[j] * m_vecFourierSinTable[tableIndex];
- }
- }
- if (direction < 0) {
- sumReal /= m_nFilterPoints;
- sumImag /= m_nFilterPoints;
- }
- output[i] = complex<double> (sumReal, sumImag);
- }
-}
-
-// (a+bi) * (c + di) = (ac - bd) + (ad + bc)i
-void
-SignalFilter::finiteFourierTransform (const complex<double> input[], complex<double> output[], int direction) const
-{
- if (direction < 0)
- direction = -1;
- 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_vecFourierCosTable[tableIndex]
- - input[j].imag() * m_vecFourierSinTable[tableIndex];
- sumImag += input[j].real() * m_vecFourierSinTable[tableIndex]
- + input[j].imag() * m_vecFourierCosTable[tableIndex];
- } else {
- sumReal += input[j].real() * m_vecFourierCosTable[tableIndex]
- - input[j].imag() * -m_vecFourierSinTable[tableIndex];
- sumImag += input[j].real() * -m_vecFourierSinTable[tableIndex]
- + input[j].imag() * m_vecFourierCosTable[tableIndex];
- }
- }
- if (direction < 0) {
- sumReal /= m_nFilterPoints;
- sumImag /= m_nFilterPoints;
- }
- output[i] = complex<double> (sumReal, sumImag);
- }
-}
-
-void
-SignalFilter::finiteFourierTransform (const complex<double> input[], double output[], int direction) const
-{
- if (direction < 0)
- direction = -1;
- 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_vecFourierCosTable[tableIndex]
- - input[j].imag() * m_vecFourierSinTable[tableIndex];
- } else {
- sumReal += input[j].real() * m_vecFourierCosTable[tableIndex]
- - input[j].imag() * -m_vecFourierSinTable[tableIndex];
- }
- }
- if (direction < 0) {
- sumReal /= m_nFilterPoints;
- }
- output[i] = sumReal;
- }
-}
-