X-Git-Url: http://git.kpe.io/?p=ctsim.git;a=blobdiff_plain;f=libctsim%2Ffilter.cpp;h=1c9e95bc37c03e372147f3349ea6dea4b75fcad7;hp=27d1829380ae5224feff90fb221a801079884f20;hb=e4c1f7f8eb87558c3abf3bf1d20732361f425351;hpb=a8ba12a8c971de1d8cb3ef1c3a7d2d9fcf45affa diff --git a/libctsim/filter.cpp b/libctsim/filter.cpp index 27d1829..1c9e95b 100644 --- a/libctsim/filter.cpp +++ b/libctsim/filter.cpp @@ -1,5 +1,5 @@ /***************************************************************************** -** FILE IDENTIFICATION +** File IDENTIFICATION ** ** Name: filter.cpp ** Purpose: Routines for signal-procesing filters @@ -9,7 +9,7 @@ ** 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 $ +** $Id: filter.cpp,v 1.18 2000/07/15 08:36:13 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 @@ -28,6 +28,8 @@ #include "ct.h" +int SignalFilter::N_INTEGRAL=500; //static member + /* NAME * SignalFilter::SignalFilter Construct a signal * @@ -40,11 +42,9 @@ * 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 (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; @@ -70,15 +70,15 @@ SignalFilter::SignalFilter (const char* filterName, const char* filterMethodName m_failMessage += domainName; return; } - init (m_idFilter, m_idFilterMethod, bw, signalIncrement, nSignalPoints, param, m_idDomain, numIntegral); + init (m_idFilter, m_idFilterMethod, bw, signalIncrement, nSignalPoints, param, m_idDomain, zeropad, preinterpolationFactor); } -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 FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalIncrement, int nSignalPoints, double param, const DomainID domainID, int zeropad = 0, int preinterpolationFactor = 1) { - init (filterID, filterMethodID, bw, signalIncrement, nSignalPoints, param, domainID, numIntegral); + init (filterID, filterMethodID, bw, signalIncrement, nSignalPoints, param, domainID, zeropad, preinterpolationFactor); } -SignalFilter::SignalFilter (const char* filterName, const char* domainName, double bw, double param, int numIntegral = 0) +SignalFilter::SignalFilter (const char* filterName, const char* domainName, double bw, double param) { m_bw = bw; m_nSignalPoints = 0; @@ -87,7 +87,6 @@ SignalFilter::SignalFilter (const char* filterName, const char* domainName, doub m_vecFourierCosTable = NULL; m_vecFourierSinTable = NULL; m_filterParam = param; - m_numIntegral = numIntegral; m_idFilter = convertFilterNameToID (filterName); if (m_idFilter == FILTER_INVALID) { m_fail = true; @@ -105,7 +104,7 @@ SignalFilter::SignalFilter (const char* filterName, const char* domainName, doub } 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 FilterID filterID, const FilterMethodID filterMethodID, double bw, double signalIncrement, int nSignalPoints, double filterParam, const DomainID domainID, int zeropad, int preinterpolationFactor) { m_bw = bw; m_idFilter = filterID; @@ -115,71 +114,103 @@ SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID m_fail = true; return; } + m_traceLevel = TRACE_NONE; 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_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 + m_fail = true; + m_failMessage = "FFT not yet implemented"; + 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_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_2 || m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_4) { + if (m_zeropad > 0) { double logBase2 = log(m_nSignalPoints) / log(2); - int nextPowerOf2 = static_cast(floor(logBase2)) + 1; - if (m_idFilterMethod == FILTER_METHOD_FFT_ZEROPAD_4) - nextPowerOf2++; + int nextPowerOf2 = static_cast(floor(logBase2)); if (logBase2 != floor(logBase2)) nextPowerOf2++; + nextPowerOf2 += (m_zeropad - 1); m_nFilterPoints = 1 << nextPowerOf2; - cout << "nFilterPoints = " << m_nFilterPoints << endl; + if (m_traceLevel >= TRACE_TEXT) + cout << "nFilterPoints = " << m_nFilterPoints << endl; } - m_filterMin = 0; - m_filterMax = m_nSignalPoints * m_signalInc; - m_filterInc = (m_filterMax - m_filterMin) / (m_nFilterPoints - 1); + 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(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; + for (int i = 0; i <= halfFilter; i++) + m_vecFilter[i] = static_cast(i) / halfFilter/ (2. * m_signalInc); + for (int i = 1; i <= halfFilter; i++) + m_vecFilter[m_nFilterPoints - i] = static_cast(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; + } + } #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 (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; } + 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_numIntegral = numint; m_vecFilter = new double[ m_nFilterPoints ]; if (m_idFilter == FILTER_SHEPP) { @@ -195,15 +226,15 @@ SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID double x; int i; for (x = m_filterMin, i = 0; i < m_nFilterPoints; x += m_filterInc, i++) - m_vecFilter[i] = frequencyResponse (x, param); + 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 (numint == 0) - m_vecFilter[i] = spatialResponseAnalytic (x, param); + if (haveAnalyticSpatial(m_idFilter)) + m_vecFilter[i] = spatialResponseAnalytic (x, m_filterParam); else - m_vecFilter[i] = spatialResponseCalc (x, param, numint); + m_vecFilter[i] = spatialResponseCalc (x, m_filterParam); } else { m_failMessage = "Illegal domain name "; m_failMessage += m_idDomain; @@ -214,13 +245,22 @@ SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID SignalFilter::~SignalFilter (void) { - delete m_vecFilter; - delete m_vecFourierSinTable; - delete m_vecFourierCosTable; + 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); + 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 } @@ -293,14 +333,16 @@ SignalFilter::convertFilterMethodNameToID (const char* const filterMethodName) fmID = FILTER_METHOD_CONVOLUTION; else if (strcasecmp (filterMethodName, FILTER_METHOD_FOURIER_STR) == 0) fmID = FILTER_METHOD_FOURIER; + else if (strcasecmp (filterMethodName, FILTER_METHOD_FOURIER_TABLE_STR) == 0) + fmID = FILTER_METHOD_FOURIER_TABLE; 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; +#if HAVE_FFTW + else if (strcasecmp (filterMethodName, FILTER_METHOD_FFTW_STR) == 0) + fmID = FILTER_METHOD_FFTW; + else if (strcasecmp (filterMethodName, FILTER_METHOD_RFFTW_STR) == 0) + fmID = FILTER_METHOD_RFFTW; +#endif return (fmID); } @@ -314,14 +356,16 @@ SignalFilter::convertFilterMethodIDToName (const FilterMethodID fmID) return (FILTER_METHOD_CONVOLUTION_STR); else if (fmID == FILTER_METHOD_FOURIER) return (FILTER_METHOD_FOURIER_STR); + else if (fmID == FILTER_METHOD_FOURIER_TABLE) + return (FILTER_METHOD_FOURIER_TABLE_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); +#if HAVE_FFTW + else if (fmID == FILTER_METHOD_FFTW) + return (FILTER_METHOD_FFTW_STR); + else if (fmID == FILTER_METHOD_RFFTW) + return (FILTER_METHOD_RFFTW_STR); +#endif return (name); } @@ -352,7 +396,6 @@ SignalFilter::convertDomainIDToName (const DomainID domain) return (name); } - void SignalFilter::filterSignal (const float input[], double output[]) const { @@ -360,33 +403,66 @@ SignalFilter::filterSignal (const float input[], double output[]) const 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); + 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 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 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] = sqrt (in[i].re * in[i].re + in[i].im * in[i].im); + 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 @@ -395,7 +471,7 @@ 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_bw, x, m_filterParam); else if (m_idDomain == DOMAIN_FREQUENCY) response = frequencyResponse (m_idFilter, m_bw, x, m_filterParam); @@ -404,12 +480,12 @@ SignalFilter::response (double x) double -SignalFilter::spatialResponse (FilterID filterID, double bw, double x, double param, int nIntegral = 0) +SignalFilter::spatialResponse (FilterID 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); } /* NAME @@ -428,9 +504,9 @@ SignalFilter::spatialResponse (FilterID filterID, double bw, double x, double pa */ double -SignalFilter::spatialResponseCalc (double x, double param, int nIntegral) const +SignalFilter::spatialResponseCalc (double x, double param) const { - return (spatialResponseCalc (m_idFilter, m_bw, x, param, nIntegral)); + return (spatialResponseCalc (m_idFilter, m_bw, x, param, N_INTEGRAL)); } double @@ -562,6 +638,30 @@ SignalFilter::spatialResponseAnalytic (double x, double param) const return spatialResponseAnalytic (m_idFilter, m_bw, x, param); } +const bool +SignalFilter::haveAnalyticSpatial (FilterID filterID) +{ + bool haveAnalytic = false; + + switch (filterID) { + case FILTER_BANDLIMIT: + case FILTER_TRIANGLE: + case FILTER_COSINE: + case FILTER_G_HAMMING: + case FILTER_ABS_BANDLIMIT: + case FILTER_ABS_COSINE: + case FILTER_ABS_G_HAMMING: + case FILTER_SHEPP: + case FILTER_SINC: + haveAnalytic = true; + break; + default: + break; + } + + return (haveAnalytic); +} + double SignalFilter::spatialResponseAnalytic (FilterID filterID, double bw, double x, double param) { @@ -716,19 +816,19 @@ for (int i = 0; i < np; i++) void -SignalFilter::finiteFourierTransform (const float input[], complex output[], const int n, int direction) +SignalFilter::finiteFourierTransform (const double input[], complex output[], const int n, int direction) { if (direction < 0) direction = -1; else direction = 1; - double angleIncrement = 2 * PI / n; + 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 * direction; + double angle = i * j * angleIncrement; sumReal += input[j] * cos(angle); sumImag += input[j] * sin(angle); } @@ -749,11 +849,11 @@ SignalFilter::finiteFourierTransform (const complex input[], complex sum (0,0); for (int j = 0; j < n; j++) { - double angle = i * j * angleIncrement * direction; + double angle = i * j * angleIncrement; complex exponentTerm (cos(angle), sin(angle)); sum += input[j] * exponentTerm; } @@ -765,35 +865,56 @@ SignalFilter::finiteFourierTransform (const complex input[], complex output[], int direction) const +SignalFilter::finiteFourierTransform (const complex input[], double output[], const int n, int direction) { if (direction < 0) direction = -1; else direction = 1; - for (int i = 0; i < m_nSignalPoints; i++) { + 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 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_nSignalPoints; j++) { + for (int j = 0; j < m_nFilterPoints; j++) { int tableIndex = i * j; if (direction > 0) { - sumReal += input[i] * m_vecFourierCosTable[tableIndex]; - sumImag += input[i] * m_vecFourierSinTable[tableIndex]; + sumReal += input[j] * m_vecFourierCosTable[tableIndex]; + sumImag += input[j] * m_vecFourierSinTable[tableIndex]; } else { - sumReal += input[i] * m_vecFourierCosTable[tableIndex]; - sumImag -= input[i] * m_vecFourierSinTable[tableIndex]; + sumReal += input[j] * m_vecFourierCosTable[tableIndex]; + sumImag -= input[j] * m_vecFourierSinTable[tableIndex]; } } if (direction < 0) { - sumReal /= m_nSignalPoints; - sumImag /= m_nSignalPoints; + sumReal /= m_nFilterPoints; + sumImag /= m_nFilterPoints; } output[i] = complex (sumReal, sumImag); } } -// (a+bi) * (c + di) = (ac - db) + (bc + da)i -#if 0 +// (a+bi) * (c + di) = (ac - bd) + (ad + bc)i void SignalFilter::finiteFourierTransform (const complex input[], complex output[], int direction) const { @@ -802,30 +923,55 @@ SignalFilter::finiteFourierTransform (const complex input[], complex 0) { - sumReal += input[i] * m_vecFourierCosTable[tableIndex]; - sumImag += input[i] * m_vecFourierSinTable[tableIndex]; + 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[i] * m_vecFourierCosTable[tableIndex]; - sumImag -= input[i] * m_vecFourierSinTable[tableIndex]; + 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_nSignalPoints; - sumImag /= m_nSignalPoints; + if (direction < 0) { + sumReal /= m_nFilterPoints; + sumImag /= m_nFilterPoints; } output[i] = complex (sumReal, sumImag); } } -#endif -void -SignalFilter::dotProduct (const double v1[], const complex v2[], complex output[], const int n) +void +SignalFilter::finiteFourierTransform (const complex input[], double output[], int direction) const { - for (int i = 0; i < n; i++) - output[i] = v1[i] * v2[i]; + 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; + } } + +