X-Git-Url: http://git.kpe.io/?p=ctsim.git;a=blobdiff_plain;f=libctsim%2Fprocsignal.cpp;h=5c10c9e9ff2a44b6b9ba602c5352c52bf6c1094e;hp=e38fae239f0095e9b499425599526cfe0460de54;hb=a05f3cb550877e94aa118cc04b361c0c8fdb3dc3;hpb=6bfb747f8163381d94a02c03a0351e9ca6815d22

diff --git a/libctsim/procsignal.cpp b/libctsim/procsignal.cpp
index e38fae2..5c10c9e 100644
--- 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++)