- double xinc = (m_xmax - m_xmin) / (m_nPoints - 1);
-
- if (m_idFilter == FILTER_SHEPP) {
- double a = 2 * m_bw;
- double c = - 4. / (a * a);
- int center = (m_nPoints - 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_xmin, i = 0; i < m_nPoints; x += xinc, i++)
- m_vecFilter[i] = frequencyResponse (x, param);
- } else if (m_idDomain == DOMAIN_SPATIAL) {
- double x;
- int i;
- for (x = m_xmin, i = 0; i < m_nPoints; x += xinc, i++)
- if (numint == 0)
- m_vecFilter[i] = spatialResponseAnalytic (x, param);
- else
- m_vecFilter[i] = spatialResponseCalc (x, param, numint);
- } else {
+ // 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
+ 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_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);
+ } else {