X-Git-Url: http://git.kpe.io/?p=ctsim.git;a=blobdiff_plain;f=libctsim%2Ffilter.cpp;h=397f8a204120926ed04516653b5e1b2ca1d0f654;hp=27d1829380ae5224feff90fb221a801079884f20;hb=e8462f7431582627e44906239077f1c696eefba1;hpb=a8ba12a8c971de1d8cb3ef1c3a7d2d9fcf45affa diff --git a/libctsim/filter.cpp b/libctsim/filter.cpp index 27d1829..397f8a2 100644 --- a/libctsim/filter.cpp +++ b/libctsim/filter.cpp @@ -1,15 +1,13 @@ /***************************************************************************** -** FILE IDENTIFICATION -** +** File IDENTIFICATION +** ** Name: filter.cpp ** Purpose: Routines for signal-procesing filters -** Progammer: Kevin Rosenberg +** Progammer: Kevin Rosenberg ** Date Started: Aug 1984 ** ** This is part of the CTSim program -** Copyright (C) 1983-2000 Kevin Rosenberg -** -** $Id: filter.cpp,v 1.8 2000/07/04 18:33:35 kevin Exp $ +** 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 @@ -27,414 +25,339 @@ #include "ct.h" +int SignalFilter::N_INTEGRAL=500; //static member + +const int SignalFilter::FILTER_INVALID = -1 ; +const int SignalFilter::FILTER_ABS_BANDLIMIT = 0; // filter times |x| +const int SignalFilter::FILTER_ABS_G_HAMMING = 1; +const int SignalFilter::FILTER_ABS_HANNING = 2; +const int SignalFilter::FILTER_ABS_COSINE = 3; +const int SignalFilter::FILTER_ABS_SINC = 4; +const int SignalFilter::FILTER_SHEPP = 5; +const int SignalFilter::FILTER_BANDLIMIT = 6; +const int SignalFilter::FILTER_SINC = 7; +const int SignalFilter::FILTER_G_HAMMING = 8; +const int SignalFilter::FILTER_HANNING = 9; +const int SignalFilter::FILTER_COSINE = 10; +const int SignalFilter::FILTER_TRIANGLE = 11; + +const int SignalFilter::s_iReconstructFilterCount = 4; + +const char* const SignalFilter::s_aszFilterName[] = { + "abs_bandlimit", + "abs_hamming", + "abs_hanning", + "abs_cosine", + "shepp", + "abs_sinc", + "bandlimit", + "sinc", + "hamming", + "hanning", + "cosine", + "triangle" +}; + +const char* const SignalFilter::s_aszFilterTitle[] = { + "Abs(w) * Bandlimit", + "Abs(w) * Hamming", + "Abs(w) * Hanning", + "Abs(w) * Cosine", + "Shepp", + "Abs(w) * Sinc", + "Bandlimit", + "Sinc", + "Hamming", + "Hanning", + "Cosine", + "Triangle" +}; + +const int SignalFilter::s_iFilterCount = sizeof(s_aszFilterName) / sizeof(const char*); + + +const int SignalFilter::DOMAIN_INVALID = -1; +const int SignalFilter::DOMAIN_FREQUENCY = 0; +const int SignalFilter::DOMAIN_SPATIAL = 1; + +const char* const SignalFilter::s_aszDomainName[] = { + "frequency", + "spatial", +}; + +const char* const SignalFilter::s_aszDomainTitle[] = { + "Frequency", + "Spatial", +}; + +const int SignalFilter::s_iDomainCount = sizeof(s_aszDomainName) / sizeof(const char*); + /* NAME - * SignalFilter::SignalFilter Construct a signal - * - * SYNOPSIS - * f = SignalFilter (filt_type, bw, filterMin, filterMax, n, param, domain, analytic) - * double f Generated filter vector - * int filt_type Type of filter wanted - * double bw Bandwidth of filter - * double filterMin, filterMax Filter limits - * int nSignalPoints Number of points in signal - * double param General input parameter to filters - * int domain FREQUENCY or SPATIAL domain wanted - * int numint Number if intervals for calculating discrete inverse fourier xform - * for spatial domain filters. For ANALYTIC solutions, use numint = 0 - */ - -SignalFilter::SignalFilter (const char* filterName, const char* filterMethodName, double bw, double signalIncrement, int nSignalPoints, double param, const char* domainName, int numIntegral = 0) +* SignalFilter::SignalFilter Construct a signal +* +* SYNOPSIS +* f = SignalFilter (filt_type, bw, filterMin, filterMax, n, param, domain, analytic) +* double f Generated filter vector +* int filt_type Type of filter wanted +* double bw Bandwidth of filter +* double filterMin, filterMax Filter limits +* 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* szFilterName, double dFilterMinimum, double dFilterMaximum, int nFilterPoints, double dBandwidth, double dFilterParam, const char* szDomainName) +: m_adFilter(NULL), m_fail(false) { - m_vecFilter = NULL; - m_vecFourierCosTable = NULL; - m_vecFourierSinTable = NULL; - 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, numIntegral); + init (m_idFilter, dFilterMinimum, dFilterMaximum, nFilterPoints, dBandwidth, dFilterParam, m_idDomain); } -SignalFilter::SignalFilter (const FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalIncrement, int nSignalPoints, double param, const DomainID domainID, int numIntegral = 0) +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, numIntegral); + init (idFilter, dFilterMinimum, dFilterMaximum, nFilterPoints, dBandwidth, dFilterParam, idDomain); } -SignalFilter::SignalFilter (const char* filterName, const char* domainName, double bw, double param, int numIntegral = 0) +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_vecFilter = NULL; - m_vecFourierCosTable = NULL; - m_vecFourierSinTable = NULL; - m_filterParam = param; - m_numIntegral = numIntegral; - 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 FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalIncrement, int nSignalPoints, double param, const DomainID domainID, int numint) +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_nameFilter = convertFilterIDToName (m_idFilter); - m_nameDomain = convertDomainIDToName (m_idDomain); - m_nameFilterMethod = convertFilterMethodIDToName (m_idFilterMethod); - m_fail = false; - m_nSignalPoints = nSignalPoints; - m_signalInc = signalIncrement; - m_filterParam = param; - - if (m_idFilterMethod == FILTER_METHOD_FOURIER) { - int nFourier = m_nSignalPoints * m_nSignalPoints + 1; - double angleIncrement = (2. * PI) / m_nSignalPoints; - m_vecFourierCosTable = new double[ nFourier ]; - m_vecFourierSinTable = new double[ nFourier ]; - for (int i = 0; i < nFourier; i++) { - m_vecFourierCosTable[i] = cos (angleIncrement * i); - m_vecFourierSinTable[i] = sin (angleIncrement * i); - } - m_nFilterPoints = m_nSignalPoints; - m_filterMin = 0; - m_filterMax = m_nSignalPoints * m_signalInc; - m_filterInc = (m_filterMax - m_filterMin) / (m_nFilterPoints - 1); - m_vecFilter = new double [m_nFilterPoints]; - int halfFilter = m_nFilterPoints / 2; - for (int i = 0; i < halfFilter; i++) - m_vecFilter[i] = static_cast(i) / (halfFilter - 1) / (2 * m_signalInc); - for (int i = 0; i < halfFilter; i++) - m_vecFilter[m_nFilterPoints - i - 1] = static_cast(i) / (halfFilter - 1) / (2 * m_signalInc); - if (halfFilter % 2) // odd - m_vecFilter[halfFilter] = 1; - } else if (m_idFilterMethod == FILTER_METHOD_FFT || m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_2 || m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_4) { - m_nFilterPoints = m_nSignalPoints; - if (m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_2 || m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_4) { - double logBase2 = log(m_nSignalPoints) / log(2); - int nextPowerOf2 = static_cast(floor(logBase2)) + 1; - if (m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_4) - nextPowerOf2++; - if (logBase2 != floor(logBase2)) - nextPowerOf2++; - m_nFilterPoints = 1 << nextPowerOf2; - cout << "nFilterPoints = " << m_nFilterPoints << endl; - } - m_filterMin = 0; - m_filterMax = m_nSignalPoints * m_signalInc; - m_filterInc = (m_filterMax - m_filterMin) / (m_nFilterPoints - 1); - m_vecFilter = new double [m_nFilterPoints]; - int halfFilter = m_nFilterPoints / 2; - for (int i = 0; i < halfFilter; i++) - m_vecFilter[i] = static_cast(i) / (halfFilter - 1) / (2 * m_signalInc); - for (int i = 0; i < halfFilter; i++) - m_vecFilter[m_nFilterPoints - i - 1] = static_cast(i) / (halfFilter - 1) / (2 * m_signalInc); - if (halfFilter % 2) // odd - m_vecFilter[halfFilter] = 1; - -#if HAVE_FFTW - m_planForward = fftw_create_plan (m_nFilterPoints, FFTW_FORWARD, FFTW_ESTIMATE); - m_planBackward = fftw_create_plan (m_nFilterPoints, FFTW_BACKWARD, FFTW_ESTIMATE); -#endif + if (nFilterPoints < 2) { + m_fail = true; + m_failMessage = "Number of filter points "; + m_failMessage += nFilterPoints; + m_failMessage = " less than 2"; + return; } - 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_numIntegral = numint; - 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, param); - } else if (m_idDomain == DOMAIN_SPATIAL) { - double x; - int i; - for (x = m_filterMin, i = 0; i < m_nFilterPoints; x += m_filterInc, i++) - if (numint == 0) - m_vecFilter[i] = spatialResponseAnalytic (x, param); - else - m_vecFilter[i] = spatialResponseCalc (x, param, numint); - } else { - m_failMessage = "Illegal domain name "; - m_failMessage += m_idDomain; - m_fail = true; - } - } + 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; + + m_dFilterInc = (m_dFilterMax - m_dFilterMin) / (m_nFilterPoints - 1); + m_adFilter = new double [m_nFilterPoints]; + + 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_FFT) { - fftw_destroy_plan(m_planForward); - fftw_destroy_plan(m_planBackward); - } -#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); } -const SignalFilter::FilterID +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) { - FilterID filterID = FILTER_INVALID; - - if (strcasecmp (filterName, FILTER_BANDLIMIT_STR) == 0) - filterID = FILTER_BANDLIMIT; - else if (strcasecmp (filterName, FILTER_HAMMING_STR) == 0) - filterID = FILTER_G_HAMMING; - else if (strcasecmp (filterName, FILTER_SINC_STR) == 0) - filterID = FILTER_SINC; - else if (strcasecmp (filterName, FILTER_COS_STR) == 0) - filterID = FILTER_COSINE; - else if (strcasecmp (filterName, FILTER_TRIANGLE_STR) == 0) - filterID = FILTER_TRIANGLE; - else if (strcasecmp (filterName, FILTER_ABS_BANDLIMIT_STR) == 0) - filterID = FILTER_ABS_BANDLIMIT; - else if (strcasecmp (filterName, FILTER_ABS_HAMMING_STR) == 0) - filterID = FILTER_ABS_G_HAMMING; - else if (strcasecmp (filterName, FILTER_ABS_SINC_STR) == 0) - filterID = FILTER_ABS_SINC; - else if (strcasecmp (filterName, FILTER_ABS_COS_STR) == 0) - filterID = FILTER_ABS_COSINE; - else if (strcasecmp (filterName, FILTER_SHEPP_STR) == 0) - filterID = FILTER_SHEPP; - - return (filterID); + int filterID = FILTER_INVALID; + + for (int i = 0; i < s_iFilterCount; i++) { + if (strcasecmp (filterName, s_aszFilterName[i]) == 0) { + filterID = i; + break; + } + } + + return (filterID); } const char * -SignalFilter::convertFilterIDToName (const FilterID filterID) +SignalFilter::convertFilterIDToName (const int filterID) { - const char *name = ""; - - if (filterID == FILTER_SHEPP) - name = FILTER_SHEPP_STR; - else if (filterID == FILTER_ABS_COSINE) - name = FILTER_ABS_COS_STR; - else if (filterID == FILTER_ABS_SINC) - name = FILTER_ABS_SINC_STR; - else if (filterID == FILTER_ABS_G_HAMMING) - name = FILTER_ABS_HAMMING_STR; - else if (filterID == FILTER_ABS_BANDLIMIT) - name = FILTER_ABS_BANDLIMIT_STR; - else if (filterID == FILTER_COSINE) - name = FILTER_COS_STR; - else if (filterID == FILTER_SINC) - name = FILTER_SINC_STR; - else if (filterID == FILTER_G_HAMMING) - name = FILTER_HAMMING_STR; - else if (filterID == FILTER_BANDLIMIT) - name = FILTER_BANDLIMIT_STR; - else if (filterID == FILTER_TRIANGLE) - name = FILTER_TRIANGLE_STR; - + static const char *name = ""; + + if (filterID >= 0 && filterID < s_iFilterCount) + return (s_aszFilterName [filterID]); + return (name); } - -const SignalFilter::FilterMethodID -SignalFilter::convertFilterMethodNameToID (const char* const filterMethodName) -{ - FilterMethodID fmID = FILTER_METHOD_INVALID; - - if (strcasecmp (filterMethodName, FILTER_METHOD_CONVOLUTION_STR) == 0) - fmID = FILTER_METHOD_CONVOLUTION; - else if (strcasecmp (filterMethodName, FILTER_METHOD_FOURIER_STR) == 0) - fmID = FILTER_METHOD_FOURIER; - else if (strcasecmp (filterMethodName, FILTER_METHOD_FFT_STR) == 0) - fmID = FILTER_METHOD_FFT; - else if (strcasecmp (filterMethodName, FILTER_METHOD_FFT_ZEROPAD_2_STR) == 0) - fmID = FILTER_METHOD_FFT_ZEROPAD_2; - else if (strcasecmp (filterMethodName, FILTER_METHOD_FFT_ZEROPAD_4_STR) == 0) - fmID = FILTER_METHOD_FFT_ZEROPAD_4; - else if (strcasecmp (filterMethodName, FILTER_METHOD_FFT_ZEROPAD_6_STR) == 0) - fmID = FILTER_METHOD_FFT_ZEROPAD_6; - - return (fmID); -} const char * -SignalFilter::convertFilterMethodIDToName (const FilterMethodID fmID) +SignalFilter::convertFilterIDToTitle (const int filterID) { - const char *name = ""; - - if (fmID == FILTER_METHOD_CONVOLUTION) - return (FILTER_METHOD_CONVOLUTION_STR); - else if (fmID == FILTER_METHOD_FOURIER) - return (FILTER_METHOD_FOURIER_STR); - else if (fmID == FILTER_METHOD_FFT) - return (FILTER_METHOD_FFT_STR); - else if (fmID == FILTER_METHOD_FFT_ZEROPAD_2) - return (FILTER_METHOD_FFT_ZEROPAD_2_STR); - else if (fmID == FILTER_METHOD_FFT_ZEROPAD_4) - return (FILTER_METHOD_FFT_ZEROPAD_4_STR); - else if (fmID == FILTER_METHOD_FFT_ZEROPAD_6) - return (FILTER_METHOD_FFT_ZEROPAD_6_STR); + static const char *title = ""; - return (name); + if (filterID >= 0 && filterID < s_iFilterCount) { + return (s_aszFilterTitle [filterID]); + } + return (title); } -const SignalFilter::DomainID +int SignalFilter::convertDomainNameToID (const char* const domainName) { - DomainID dID = DOMAIN_INVALID; - - if (strcasecmp (domainName, DOMAIN_SPATIAL_STR) == 0) - dID = DOMAIN_SPATIAL; - else if (strcasecmp (domainName, DOMAIN_FREQUENCY_STR) == 0) - dID = DOMAIN_FREQUENCY; + int dID = DOMAIN_INVALID; + for (int i = 0; i < s_iDomainCount; i++) { + if (strcasecmp (domainName, s_aszDomainName[i]) == 0) { + dID = i; + break; + } + } return (dID); } const char * -SignalFilter::convertDomainIDToName (const DomainID domain) +SignalFilter::convertDomainIDToName (const int domainID) { - const char *name = ""; + static const char *name = ""; - if (domain == DOMAIN_SPATIAL) - return (DOMAIN_SPATIAL_STR); - else if (domain == DOMAIN_FREQUENCY) - return (DOMAIN_FREQUENCY_STR); + if (domainID >= 0 && domainID < s_iDomainCount) + return (s_aszDomainName [domainID]); return (name); } - -void -SignalFilter::filterSignal (const float input[], double output[]) const +const char * +SignalFilter::convertDomainIDToTitle (const int domainID) { - 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) { - complex fftSignal[m_nSignalPoints]; - complex complexOutput[m_nSignalPoints]; - complex filteredSignal[m_nSignalPoints]; - finiteFourierTransform (input, fftSignal, m_nSignalPoints, -1); - dotProduct (m_vecFilter, fftSignal, filteredSignal, m_nSignalPoints); - finiteFourierTransform (filteredSignal, complexOutput, m_nSignalPoints, 1); - for (int i = 0; i < m_nSignalPoints; i++) { - output[i] = abs( complexOutput[i] ); - } - } else if (m_idFilterMethod == FILTER_METHOD_FFT || FILTER_METHOD_FFT_ZEROPAD_2 || FILTER_METHOD_FFT_ZEROPAD_4) { - fftw_complex in[m_nFilterPoints], out[m_nFilterPoints]; - for (int i = 0; i < m_nSignalPoints; i++) { - in[i].re = input[i]; - in[i].im = 0; - } - for (int i = m_nSignalPoints; i < m_nFilterPoints; i++) { - in[i].re = in[i].im = 0; // ZeroPad - } - fftw_one(m_planForward, in, out); - for (int i = 0; i < m_nFilterPoints; i++) { - out[i].re = m_vecFilter[i] * out[i].re / m_nSignalPoints; - out[i].im = m_vecFilter[i] * out[i].im / m_nSignalPoints; - } - fftw_one(m_planBackward, out, in); - for (int i = 0; i < m_nSignalPoints; i++) - output[i] = sqrt (in[i].re * in[i].re + in[i].im * in[i].im); - } + static const char *title = ""; + + if (domainID >= 0 && domainID < s_iDomainCount) + return (s_aszDomainTitle [domainID]); + + return (title); } + double SignalFilter::response (double x) { double response = 0; if (m_idDomain == DOMAIN_SPATIAL) - response = spatialResponse (m_idFilter, m_bw, x, m_filterParam, m_numIntegral); + 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); } -double -SignalFilter::spatialResponse (FilterID filterID, double bw, double x, double param, int nIntegral = 0) +double +SignalFilter::spatialResponse (int filterID, double bw, double x, double param) { - if (nIntegral == 0) + if (haveAnalyticSpatial(filterID)) return spatialResponseAnalytic (filterID, bw, x, param); else - return spatialResponseCalc (filterID, bw, x, param, nIntegral); + 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 - * response - * - * SYNOPSIS - * y = filter_spatial_response_calc (filt_type, x, m_bw, param, n) - * double y Filter's response in spatial domain - * int filt_type Type of filter (definitions in ct.h) - * double x Spatial position to evaluate filter - * double m_bw Bandwidth of window - * double param General parameter for various filters - * int n Number of points to calculate integrations - */ - -double -SignalFilter::spatialResponseCalc (double x, double param, int nIntegral) const +* filter_spatial_response_calc Calculate filter by discrete inverse fourier +* transform of filters's frequency +* response +* +* SYNOPSIS +* y = filter_spatial_response_calc (filt_type, x, m_bw, param, n) +* double y Filter's response in spatial domain +* int filt_type Type of filter (definitions in ct.h) +* double x Spatial position to evaluate filter +* double m_bw Bandwidth of window +* double param General parameter for various filters +* int n Number of points to calculate integrations +*/ + +double +SignalFilter::spatialResponseCalc (double x) const { - return (spatialResponseCalc (m_idFilter, m_bw, x, param, nIntegral)); + return (spatialResponseCalc (m_idFilter, m_dBandwidth, x, m_dFilterParam, N_INTEGRAL)); } -double -SignalFilter::spatialResponseCalc (FilterID filterID, double bw, double x, double param, int n) +double +SignalFilter::spatialResponseCalc (int filterID, double bw, double x, double param, int n) { double zmin, zmax; @@ -448,122 +371,160 @@ SignalFilter::spatialResponseCalc (FilterID filterID, double bw, double x, doubl double zinc = (zmax - zmin) / (n - 1); double z = zmin; - double q [n]; + double* q = new double [n]; for (int i = 0; i < n; i++, z += zinc) q[i] = frequencyResponse (filterID, bw, z, param) * cos (TWOPI * z * x); - + double y = 2 * integrateSimpson (zmin, zmax, q, n); - + delete q; + return (y); } /* NAME - * filter_frequency_response Return filter frequency response - * - * SYNOPSIS - * h = filter_frequency_response (filt_type, u, m_bw, param) - * double h Filters frequency response at u - * int filt_type Type of filter - * double u Frequency to evaluate filter at - * double m_bw Bandwidth of filter - * double param General input parameter for various filters - */ - -double -SignalFilter::frequencyResponse (double u, double param) const +* filter_frequency_response Return filter frequency response +* +* SYNOPSIS +* h = filter_frequency_response (filt_type, u, m_bw, param) +* double h Filters frequency response at u +* int filt_type Type of filter +* double u Frequency to evaluate filter at +* double m_bw Bandwidth of filter +* double param General input parameter for various filters +*/ + +double +SignalFilter::frequencyResponse (double u) const { - return frequencyResponse (m_idFilter, m_bw, u, param); + return frequencyResponse (m_idFilter, m_dBandwidth, u, m_dFilterParam); } -double -SignalFilter::frequencyResponse (FilterID filterID, double bw, double u, double param) +double +SignalFilter::frequencyResponse (int filterID, double bw, double u, double param) { double q; double au = fabs (u); + double abw = fabs (bw); switch (filterID) { case FILTER_BANDLIMIT: - if (au >= bw / 2) + if (au >= (abw / 2) + F_EPSILON) q = 0.; else q = 1; break; case FILTER_ABS_BANDLIMIT: - if (au >= bw / 2) + if (au >= (abw / 2) + F_EPSILON) q = 0.; else q = au; break; case FILTER_TRIANGLE: - if (au >= bw) + if (au >= (abw / 2) + F_EPSILON) q = 0; else - q = 1 - au / bw; + q = 1 - au / abw; break; case FILTER_COSINE: - if (au >= bw / 2) + if (au >= (abw / 2) + F_EPSILON) q = 0; else - q = cos(PI * u / bw); + q = cos(PI * au / abw); break; case FILTER_ABS_COSINE: - if (au >= bw / 2) + if (au >= (abw / 2) + F_EPSILON) q = 0; else - q = au * cos(PI * u / bw); + q = au * cos(PI * au / abw); break; case FILTER_SINC: - q = bw * sinc (PI * bw * u, 1.); + q = abw * sinc (PI * abw * au, 1.); break; case FILTER_ABS_SINC: - q = au * bw * sinc (PI * bw * u, 1.); + if (au >= (abw / 2) + F_EPSILON) + q = 0; + else + q = au * abw * sinc (PI * abw * au, 1.); break; + case FILTER_HANNING: + param = 0.5; + // follow through to G_HAMMING case FILTER_G_HAMMING: - if (au >= bw / 2) + if (au >= (abw / 2) + F_EPSILON) q = 0; else - q = param + (1 - param) * cos (TWOPI * u / bw); + q = param + (1 - param) * cos (TWOPI * au / abw); break; + case FILTER_ABS_HANNING: + param = 0.5; + // follow through to ABS_G_HAMMING case FILTER_ABS_G_HAMMING: - if (au >= bw / 2) + if (au >= (abw / 2) + F_EPSILON) q = 0; else - q = au * (param + (1 - param) * cos(TWOPI * u / bw)); + q = au * (param + (1 - param) * cos(TWOPI * au / abw)); break; default: q = 0; sys_error (ERR_WARNING, "Frequency response for filter %d not implemented [filter_frequency_response]", filterID); break; } + return (q); } /* NAME - * filter_spatial_response_analytic Calculate filter by analytic inverse fourier - * transform of filters's frequency - * response - * - * SYNOPSIS - * y = filter_spatial_response_analytic (filt_type, x, m_bw, param) - * double y Filter's response in spatial domain - * int filt_type Type of filter (definitions in ct.h) - * double x Spatial position to evaluate filter - * double m_bw Bandwidth of window - * double param General parameter for various filters - */ - -double -SignalFilter::spatialResponseAnalytic (double x, double param) const +* filter_spatial_response_analytic Calculate filter by analytic inverse fourier +* transform of filters's frequency +* response +* +* SYNOPSIS +* y = filter_spatial_response_analytic (filt_type, x, m_bw, param) +* double y Filter's response in spatial domain +* int filt_type Type of filter (definitions in ct.h) +* double x Spatial position to evaluate filter +* double m_bw Bandwidth of window +* double param General parameter for various filters +*/ + +double +SignalFilter::spatialResponseAnalytic (double x) const { - return spatialResponseAnalytic (m_idFilter, m_bw, x, param); + return spatialResponseAnalytic (m_idFilter, m_dBandwidth, x, m_dFilterParam); +} + +const bool +SignalFilter::haveAnalyticSpatial (int filterID) +{ + bool haveAnalytic = false; + + switch (filterID) { + case FILTER_BANDLIMIT: + case FILTER_TRIANGLE: + case FILTER_COSINE: + case FILTER_G_HAMMING: + case FILTER_HANNING: + case FILTER_ABS_BANDLIMIT: + case FILTER_ABS_COSINE: + case FILTER_ABS_G_HAMMING: + case FILTER_ABS_HANNING: + case FILTER_SHEPP: + case FILTER_SINC: + haveAnalytic = true; + break; + default: + break; + } + + return (haveAnalytic); } -double -SignalFilter::spatialResponseAnalytic (FilterID filterID, double bw, double x, double param) +double +SignalFilter::spatialResponseAnalytic (int filterID, double bw, double x, double param) { double q, temp; double u = TWOPI * x; @@ -582,6 +543,9 @@ SignalFilter::spatialResponseAnalytic (FilterID filterID, double bw, double x, d case FILTER_COSINE: q = sinc(b-u,w) + sinc(b+u,w); break; + case FILTER_HANNING: + param = 0.5; + // follow through to G_HAMMING case FILTER_G_HAMMING: q = 2 * param * sin(u*w)/u + (1-param) * (sinc(b2-u, w) + sinc(b2+u, w)); break; @@ -591,6 +555,9 @@ SignalFilter::spatialResponseAnalytic (FilterID filterID, double bw, double x, d case FILTER_ABS_COSINE: q = integral_abscos(b-u,w) + integral_abscos(b+u,w); break; + case FILTER_ABS_HANNING: + param = 0.5; + // follow through to ABS_G_HAMMING case FILTER_ABS_G_HAMMING: q = 2 * param * integral_abscos(u,w) + (1-param)*(integral_abscos(u-b2,w)+integral_abscos(u+b2,w)); @@ -613,219 +580,26 @@ SignalFilter::spatialResponseAnalytic (FilterID filterID, double bw, double x, d q = 0; break; } - - return (q); -} - - -/* NAME - * sinc Return sin(x)/x function - * - * SYNOPSIS - * v = sinc (x, mult) - * double v sinc value - * double x, mult - * - * DESCRIPTION - * v = sin(x * mult) / x; - */ - -/* NAME - * integral_abscos Returns integral of u*cos(u) - * - * SYNOPSIS - * q = integral_abscos (u, w) - * double q Integral value - * double u Integration variable - * double w Upper integration boundary - * - * DESCRIPTION - * 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); + return (q); } -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); -} +// Functions that are inline in filter.h -void -SignalFilter::finiteFourierTransform (const float input[], complex output[], const int n, int direction) -{ - if (direction < 0) - direction = -1; - else - direction = 1; - - double angleIncrement = 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 * direction; - sumReal += input[j] * cos(angle); - sumImag += input[j] * sin(angle); - } - if (direction < 0) { - sumReal /= n; - sumImag /= n; - } - output[i] = complex (sumReal, sumImag); - } -} +// sinc Return sin(x)/x function +// v = sinc (x, mult) +// Calculates sin(x * mult) / x; -void -SignalFilter::finiteFourierTransform (const complex input[], complex output[], const int n, int direction) -{ - if (direction < 0) - direction = -1; - else - direction = 1; - - double angleIncrement = 2 * PI / n; - for (int i = 0; i < n; i++) { - complex sum (0,0); - for (int j = 0; j < n; j++) { - double angle = i * j * angleIncrement * direction; - complex exponentTerm (cos(angle), sin(angle)); - sum += input[j] * exponentTerm; - } - if (direction < 0) { - sum /= n; - } - output[i] = sum; - } -} +// integral_abscos Returns integral of u*cos(u) +// +// q = integral_abscos (u, w) +// double q Integral value +// double u Integration variable +// double w Upper integration boundary +// Returns the value of integral of u*cos(u)*dV for V = 0 to w -void -SignalFilter::finiteFourierTransform (const float input[], complex output[], int direction) const -{ - if (direction < 0) - direction = -1; - else - direction = 1; - - for (int i = 0; i < m_nSignalPoints; i++) { - double sumReal = 0, sumImag = 0; - for (int j = 0; j < m_nSignalPoints; j++) { - int tableIndex = i * j; - if (direction > 0) { - sumReal += input[i] * m_vecFourierCosTable[tableIndex]; - sumImag += input[i] * m_vecFourierSinTable[tableIndex]; - } else { - sumReal += input[i] * m_vecFourierCosTable[tableIndex]; - sumImag -= input[i] * m_vecFourierSinTable[tableIndex]; - } - } - if (direction < 0) { - sumReal /= m_nSignalPoints; - sumImag /= m_nSignalPoints; - } - output[i] = complex (sumReal, sumImag); - } -} -// (a+bi) * (c + di) = (ac - db) + (bc + da)i -#if 0 -void -SignalFilter::finiteFourierTransform (const complex input[], complex output[], int direction) const -{ - if (direction < 0) - direction = -1; - else - direction = 1; - - for (int i = 0; i < m_nSignalPoints; i++) { - double sumReal = 0, sumImag = 0; - for (int j = 0; j < m_nSignalPoints; j++) { - int tableIndex = i * j; - if (direction > 0) { - sumReal += input[i] * m_vecFourierCosTable[tableIndex]; - sumImag += input[i] * m_vecFourierSinTable[tableIndex]; - } else { - sumReal += input[i] * m_vecFourierCosTable[tableIndex]; - sumImag -= input[i] * m_vecFourierSinTable[tableIndex]; - } - } - if (direction > 0) { - sumReal /= m_nSignalPoints; - sumImag /= m_nSignalPoints; - } - output[i] = complex (sumReal, sumImag); - } -} -#endif -void -SignalFilter::dotProduct (const double v1[], const complex v2[], complex output[], const int n) -{ - for (int i = 0; i < n; i++) - output[i] = v1[i] * v2[i]; -}