r186: *** empty log message ***

[ctsim.git] / libctsim / procsignal.cpp

diff --git a/libctsim/procsignal.cpp b/libctsim/procsignal.cpp
index e38fae239f0095e9b499425599526cfe0460de54..5c10c9e9ff2a44b6b9ba602c5352c52bf6c1094e 100644 (file)
--- a/libctsim/procsignal.cpp
+++ b/libctsim/procsignal.cpp
@@ -9,7 +9,7 @@
 **  This is part of the CTSim program
 **  Copyright (C) 1983-2000 Kevin Rosenberg
 **
-**  $Id: procsignal.cpp,v 1.4 2000/08/27 20:32:55 kevin Exp $
+**  $Id: procsignal.cpp,v 1.5 2000/08/31 08:38:58 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
@@ -77,7 +77,7 @@ const int ProcessSignal::s_iFilterGenerationCount = sizeof(s_aszFilterGeneration
 // CLASS IDENTIFICATION
 //   ProcessSignal
 //
-ProcessSignal::ProcessSignal (const char* szFilterName, const char* szFilterMethodName, double dBandwidth, double dSignalIncrement, int nSignalPoints, double dFilterParam, const char* szDomainName, const char* szFilterGenerationName, int iZeropad, int iPreinterpolationFactor, int iTraceLevel, int iGeometry)
+ProcessSignal::ProcessSignal (const char* szFilterName, const char* szFilterMethodName, double dBandwidth, double dSignalIncrement, int nSignalPoints, double dFilterParam, const char* szDomainName, const char* szFilterGenerationName, int iZeropad, int iPreinterpolationFactor, int iTraceLevel, int iGeometry, double dFocalLength)
     : m_adFourierCosTable(NULL), m_adFourierSinTable(NULL), m_adFilter(NULL), m_fail(false)
 {
   m_idFilterMethod = convertFilterMethodNameToID (szFilterMethodName);
@@ -109,18 +109,19 @@ ProcessSignal::ProcessSignal (const char* szFilterName, const char* szFilterMeth
     return;
   }
 
-  init (m_idFilter, m_idFilterMethod, dBandwidth, dSignalIncrement, nSignalPoints, dFilterParam, m_idDomain, m_idFilterGeneration, iZeropad, iPreinterpolationFactor, iTraceLevel, iGeometry);
+  init (m_idFilter, m_idFilterMethod, dBandwidth, dSignalIncrement, nSignalPoints, dFilterParam, m_idDomain, m_idFilterGeneration, iZeropad, iPreinterpolationFactor, iTraceLevel, iGeometry, dFocalLength);
 }
 
 
 void
-ProcessSignal::init (const int idFilter, const int idFilterMethod, double dBandwidth, double dSignalIncrement, int nSignalPoints, double dFilterParam, const int idDomain, const int idFilterGeneration, const int iZeropad, const int iPreinterpolationFactor, int iTraceLevel, int iGeometry)
+ProcessSignal::init (const int idFilter, const int idFilterMethod, double dBandwidth, double dSignalIncrement, int nSignalPoints, double dFilterParam, const int idDomain, const int idFilterGeneration, const int iZeropad, const int iPreinterpolationFactor, int iTraceLevel, int iGeometry, double dFocalLength)
 {
   m_idFilter = idFilter;
   m_idDomain = idDomain;
   m_idFilterMethod = idFilterMethod;
   m_idFilterGeneration = idFilterGeneration;
   m_idGeometry = iGeometry;
+  m_dFocalLength = dFocalLength;
 
   if (m_idFilter == SignalFilter::FILTER_INVALID || m_idDomain == SignalFilter::DOMAIN_INVALID || m_idFilterMethod == FILTER_METHOD_INVALID || m_idFilterGeneration == FILTER_GENERATION_INVALID) {
     m_fail = true;
@@ -136,6 +137,13 @@ ProcessSignal::init (const int idFilter, const int idFilterMethod, double dBandw
   m_iZeropad = iZeropad;
   m_iPreinterpolationFactor = iPreinterpolationFactor;
 
+  // scale signalInc/BW to signalInc/2 to adjust for imaginary detector
+  // through origin of phantom, see Kak-Slaney Fig 3.22, for Collinear
+  if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
+    m_dSignalInc /= 2;
+    m_dBandwidth *= 2;
+  }
+
   if (m_idFilterMethod == FILTER_METHOD_FFT) {
 #if HAVE_FFTW
     m_idFilterMethod = FILTER_METHOD_RFFTW;
@@ -222,10 +230,24 @@ ProcessSignal::init (const int idFilter, const int idFilterMethod, double dBandw
            m_adFilter[i] /= m_dSignalInc;
        }
     }
-  } 
+    if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
+       for (int i = 0; i < m_nFilterPoints; i++)
+           m_adFilter[i] *= 0.5;
+    } else if (m_idGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
+       for (int i = 0; i < m_nFilterPoints; i++) {
+         int iDetFromZero = i - ((m_nFilterPoints - 1) / 2);
+         double sinScale = sin (iDetFromZero * m_dSignalInc);
+         if (fabs(sinScale) < 1E-7)
+             sinScale = 1;
+         else
+             sinScale = (iDetFromZero * m_dSignalInc) / sinScale;
+         double dScale = 0.5 * sinScale * sinScale;
+         m_adFilter[i] *= dScale;
+       }
+    } // if (geometry)
+  } // if (spatial filtering)
 
-  // Frequency-based filtering
-  else if (m_bFrequencyFiltering) {
+  else if (m_bFrequencyFiltering) {  // Frequency-based filtering
 
     if (m_idFilterGeneration == FILTER_GENERATION_DIRECT) {
       // calculate number of filter points with zeropadding
@@ -256,6 +278,22 @@ ProcessSignal::init (const int idFilter, const int idFilterMethod, double dBandw
       SignalFilter filter (m_idFilter, m_dFilterMin, m_dFilterMax, m_nFilterPoints, m_dBandwidth, m_dFilterParam, SignalFilter::DOMAIN_FREQUENCY);
       m_adFilter = new double [m_nFilterPoints];
       filter.copyFilterData (m_adFilter, 0, m_nFilterPoints);
+
+      if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
+       for (int i = 0; i < m_nFilterPoints; i++)
+         m_adFilter[i] *= 0.5;
+      } else if (m_idGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
+       for (int i = 0; i < m_nFilterPoints; i++) {
+         int iDetFromZero = i - ((m_nFilterPoints - 1) / 2);
+         double sinScale = sin (iDetFromZero * m_dSignalInc);
+         if (fabs(sinScale) < 1E-7)
+           sinScale = 1;
+         else
+           sinScale = (iDetFromZero * m_dSignalInc) / sinScale;
+         double dScale = 0.5 * sinScale * sinScale;
+         //      m_adFilter[i] *= dScale;
+       }
+      }
       if (m_traceLevel >= Trace::TRACE_PLOT) {
        SGPDriver sgpDriver ("Frequency Filter: Natural Order");
        SGP sgp (sgpDriver);
@@ -311,6 +349,21 @@ ProcessSignal::init (const int idFilter, const int idFilterMethod, double dBandw
        cio_put_str ("Press any key to continue");
        cio_kb_getc ();
       }
+      if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
+       for (int i = 0; i < m_nFilterPoints; i++)
+         adSpatialFilter[i] *= 0.5;
+      } else if (m_idGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
+       for (int i = 0; i < m_nFilterPoints; i++) {
+         int iDetFromZero = i - ((m_nFilterPoints - 1) / 2);
+         double sinScale = sin (iDetFromZero * m_dSignalInc);
+         if (fabs(sinScale) < 1E-7)
+           sinScale = 1;
+         else
+           sinScale = (iDetFromZero * m_dSignalInc) / sinScale;
+         double dScale = 0.5 * sinScale * sinScale;
+         adSpatialFilter[i] *= dScale;
+       }
+      }
       for (int i = nSpatialPoints; i < m_nFilterPoints; i++)
        adSpatialFilter[i] = 0;
 
@@ -470,11 +523,26 @@ ProcessSignal::convertFilterGenerationIDToTitle (const int fgID)
 }
 
 void
-ProcessSignal::filterSignal (const float input[], double output[], int iView) const
+ProcessSignal::filterSignal (const float constInput[], double output[]) const
 {
+  double input [m_nSignalPoints];
+  for (int i = 0; i < m_nSignalPoints; i++)
+    input[i] = constInput[i];
+
+  if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
+    for (int i = 0; i < m_nSignalPoints; i++) {
+      int iDetFromCenter = i - (m_nSignalPoints / 2);
+      input[i] *= m_dFocalLength / sqrt (m_dFocalLength * m_dFocalLength + iDetFromCenter * iDetFromCenter * m_dSignalInc * m_dSignalInc);
+    }
+  } else if (m_idGeometry == Scanner::GEOMETRY_EQUIANGULAR) {
+    for (int i = 0; i < m_nSignalPoints; i++) {
+      int iDetFromCenter = i - (m_nSignalPoints / 2);
+      input[i] *= m_dFocalLength * cos (iDetFromCenter * m_dSignalInc);
+    }
+  }
   if (m_idFilterMethod == FILTER_METHOD_CONVOLUTION) {
-    for (int i = 0; i < m_nSignalPoints; i++)
-      output[i] = convolve (input, m_dSignalInc, i, m_nSignalPoints);
+      for (int i = 0; i < m_nSignalPoints; i++)
+       output[i] = convolve (input, m_dSignalInc, i, m_nSignalPoints);
   } else if (m_idFilterMethod == FILTER_METHOD_FOURIER) {
     double inputSignal[m_nFilterPoints];
     for (int i = 0; i < m_nSignalPoints; i++)