X-Git-Url: http://git.kpe.io/?p=ctsim.git;a=blobdiff_plain;f=libctsim%2Ffilter.cpp;h=6a344d42a6273957a8d847c264bcdebd438c0357;hp=0a24996805bba3a24f48bdb83c1bd1900c9b5e04;hb=6435258bbafabf9a4ce4445edfd97f771318eb6d;hpb=a2a9671aff06827cec6d6b80234b90128d337e40 diff --git a/libctsim/filter.cpp b/libctsim/filter.cpp index 0a24996..6a344d4 100644 --- a/libctsim/filter.cpp +++ b/libctsim/filter.cpp @@ -9,7 +9,7 @@ ** This is part of the CTSim program ** Copyright (C) 1983-2000 Kevin Rosenberg ** -** $Id: filter.cpp,v 1.13 2000/07/06 08:30:30 kevin Exp $ +** $Id: filter.cpp,v 1.14 2000/07/06 18:37:24 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 @@ -49,7 +49,6 @@ SignalFilter::SignalFilter (const char* filterName, const char* filterMethodName m_vecFilter = NULL; m_vecFourierCosTable = NULL; m_vecFourierSinTable = NULL; - m_vecFftInput = NULL; m_idFilter = convertFilterNameToID (filterName); if (m_idFilter == FILTER_INVALID) { m_fail = true; @@ -87,7 +86,6 @@ SignalFilter::SignalFilter (const char* filterName, const char* domainName, doub m_vecFilter = NULL; m_vecFourierCosTable = NULL; m_vecFourierSinTable = NULL; - m_vecFftInput = NULL; m_filterParam = param; m_numIntegral = numIntegral; m_idFilter = convertFilterNameToID (filterName); @@ -130,19 +128,18 @@ SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID m_vecFourierCosTable = NULL; m_vecFourierSinTable = NULL; m_vecFilter = NULL; - m_vecFftInput = NULL; if (m_idFilterMethod == FILTER_METHOD_FFT) m_idFilterMethod = FILTER_METHOD_FFTW; - if (m_idFilterMethod == FILTER_METHOD_FOURIER || m_idFilterMethod == FILTER_METHOD_FFT || m_idFilterMethod == FILTER_METHOD_FFTW) { + if (m_idFilterMethod == FILTER_METHOD_FOURIER || FILTER_METHOD_FOURIER_TABLE || m_idFilterMethod == FILTER_METHOD_FFT || m_idFilterMethod == FILTER_METHOD_FFTW || m_idFilterMethod == FILTER_METHOD_RFFTW) { m_nFilterPoints = m_nSignalPoints; if (m_zeropad > 0) { double logBase2 = log(m_nSignalPoints) / log(2); int nextPowerOf2 = static_cast(floor(logBase2)); if (logBase2 != floor(logBase2)) nextPowerOf2++; - nextPowerOf2 += m_zeropad; + nextPowerOf2 += (m_zeropad - 1); m_nFilterPoints = 1 << nextPowerOf2; cout << "nFilterPoints = " << m_nFilterPoints << endl; } @@ -158,7 +155,7 @@ SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID } // precalculate sin and cosine tables for fourier transform - if (m_idFilterMethod == FILTER_METHOD_FOURIER) { + if (m_idFilterMethod == FILTER_METHOD_FOURIER_TABLE) { int nFourier = m_nFilterPoints * m_nFilterPoints + 1; double angleIncrement = (2. * PI) / m_nFilterPoints; m_vecFourierCosTable = new double[ nFourier ]; @@ -172,15 +169,25 @@ SignalFilter::init (const FilterID filterID, const FilterMethodID filterMethodID } #if HAVE_FFTW - if (m_idFilterMethod == FILTER_METHOD_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_planForward = fftw_create_plan (m_nFilterPoints, FFTW_FORWARD, FFTW_ESTIMATE); - m_planBackward = fftw_create_plan (m_nFilterPoints, FFTW_BACKWARD, FFTW_ESTIMATE); - m_vecFftInput = new fftw_complex [ m_nFilterPoints ]; - for (int i = 0; i < m_nFilterPoints; i++) - m_vecFftInput[i].re = m_vecFftInput[i].im = 0; + if (m_idFilterMethod == FILTER_METHOD_RFFTW) { + m_complexPlanForward = m_complexPlanBackward = NULL; + m_realPlanForward = rfftw_create_plan (m_nFilterPoints, FFTW_REAL_TO_COMPLEX, FFTW_ESTIMATE); + m_realPlanBackward = rfftw_create_plan (m_nFilterPoints, FFTW_COMPLEX_TO_REAL, FFTW_ESTIMATE); + m_vecRealFftInput = new fftw_real [ m_nFilterPoints ]; + for (int i = 0; i < m_nFilterPoints; i++) + m_vecRealFftInput[i] = 0; + } else if (m_idFilterMethod == FILTER_METHOD_FFTW) { + m_realPlanForward = m_realPlanBackward = NULL; + m_complexPlanForward = fftw_create_plan (m_nFilterPoints, FFTW_FORWARD, FFTW_ESTIMATE); + m_complexPlanBackward = fftw_create_plan (m_nFilterPoints, FFTW_BACKWARD, FFTW_ESTIMATE); + m_vecComplexFftInput = new fftw_complex [ m_nFilterPoints ]; + for (int i = 0; i < m_nFilterPoints; i++) + m_vecComplexFftInput[i].re = m_vecComplexFftInput[i].im = 0; } #endif @@ -227,11 +234,17 @@ SignalFilter::~SignalFilter (void) delete [] m_vecFilter; delete [] m_vecFourierSinTable; delete [] m_vecFourierCosTable; - delete [] m_vecFftInput; + #if HAVE_FFTW if (m_idFilterMethod == FILTER_METHOD_FFTW) { - fftw_destroy_plan(m_planForward); - fftw_destroy_plan(m_planBackward); + fftw_destroy_plan(m_complexPlanForward); + fftw_destroy_plan(m_complexPlanBackward); + delete [] m_vecComplexFftInput; + } + if (m_idFilterMethod == FILTER_METHOD_RFFTW) { + rfftw_destroy_plan(m_realPlanForward); + rfftw_destroy_plan(m_realPlanBackward); + delete [] m_vecRealFftInput; } #endif } @@ -304,10 +317,14 @@ 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_FFTW_STR) == 0) fmID = FILTER_METHOD_FFTW; + else if (strcasecmp (filterMethodName, FILTER_METHOD_RFFTW_STR) == 0) + fmID = FILTER_METHOD_RFFTW; return (fmID); } @@ -321,10 +338,14 @@ 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_FFTW) return (FILTER_METHOD_FFTW_STR); + else if (fmID == FILTER_METHOD_RFFTW) + return (FILTER_METHOD_RFFTW_STR); return (name); } @@ -363,33 +384,60 @@ 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) { + 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]; - complex complexOutput[m_nFilterPoints]; + finiteFourierTransform (inputSignal, fftSignal, m_nFilterPoints, -1); complex filteredSignal[m_nFilterPoints]; + dotProduct (m_vecFilter, fftSignal, filteredSignal, m_nFilterPoints); + double inverseFourier[m_nFilterPoints]; + finiteFourierTransform (filteredSignal, 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 - finiteFourierTransform (inputSignal, fftSignal, m_nFilterPoints, -1); + complex fftSignal[m_nFilterPoints]; + finiteFourierTransform (inputSignal, fftSignal, -1); + complex filteredSignal[m_nFilterPoints]; dotProduct (m_vecFilter, fftSignal, filteredSignal, m_nFilterPoints); - finiteFourierTransform (filteredSignal, complexOutput, m_nFilterPoints, 1); + double inverseFourier[m_nFilterPoints]; + finiteFourierTransform (filteredSignal, inverseFourier, 1); for (int i = 0; i < m_nSignalPoints; i++) - output[i] = complexOutput[i].real(); + output[i] = inverseFourier[i]; } #if HAVE_FFTW - else if (m_idFilterMethod == FILTER_METHOD_FFTW) { + else if (m_idFilterMethod == FILTER_METHOD_RFFTW) { for (int i = 0; i < m_nSignalPoints; i++) - m_vecFftInput[i].re = input[i]; + m_vecRealFftInput[i] = input[i]; + + fftw_real out[m_nFilterPoints]; + rfftw_one (m_realPlanForward, m_vecRealFftInput, out); + for (int i = 0; i < m_nFilterPoints; i++) { + out[i] *= m_vecFilter[i]; + } + fftw_real outFiltered[m_nFilterPoints]; + rfftw_one(m_realPlanBackward, out, outFiltered); + for (int i = 0; i < m_nSignalPoints; i++) + output[i] = outFiltered[i]; + } else if (m_idFilterMethod == FILTER_METHOD_FFTW) { + for (int i = 0; i < m_nSignalPoints; i++) + m_vecComplexFftInput[i].re = input[i]; fftw_complex out[m_nFilterPoints]; - fftw_one(m_planForward, m_vecFftInput, out); + fftw_one(m_complexPlanForward, m_vecComplexFftInput, out); for (int i = 0; i < m_nFilterPoints; i++) { - out[i].re = m_vecFilter[i] * out[i].re; - out[i].im = m_vecFilter[i] * out[i].im; + out[i].re *= m_vecFilter[i]; + out[i].im *= m_vecFilter[i]; } fftw_complex outFiltered[m_nFilterPoints]; - fftw_one(m_planBackward, out, outFiltered); + fftw_one(m_complexPlanBackward, out, outFiltered); for (int i = 0; i < m_nSignalPoints; i++) output[i] = outFiltered[i].re; } @@ -756,11 +804,11 @@ 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; } @@ -771,6 +819,28 @@ SignalFilter::finiteFourierTransform (const complex input[], complex 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 output[], int direction) const { @@ -784,11 +854,11 @@ SignalFilter::finiteFourierTransform (const double input[], complex outp 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) { @@ -799,8 +869,7 @@ SignalFilter::finiteFourierTransform (const double input[], complex outp } } -// (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 { @@ -809,26 +878,57 @@ 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::finiteFourierTransform (const complex 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; + } +} + void SignalFilter::dotProduct (const double v1[], const complex v2[], complex output[], const int n)