r591: Added Center-Detector length to scanning and reconstruction

[ctsim.git] / libctsim / procsignal.cpp

diff --git a/libctsim/procsignal.cpp b/libctsim/procsignal.cpp
index b5c6678c2d6c0c605032d2d3d219353d4d521a84..c503096945d4dc48ca997eb32a1cd9fc818cb530 100644 (file)
--- a/libctsim/procsignal.cpp
+++ b/libctsim/procsignal.cpp
@@ -9,7 +9,7 @@
 **  This is part of the CTSim program
 **  Copyright (c) 1983-2001 Kevin Rosenberg
 **
-**  $Id: procsignal.cpp,v 1.26 2001/02/22 18:22:40 kevin Exp $
+**  $Id: procsignal.cpp,v 1.27 2001/03/01 07:30:49 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
@@ -84,7 +84,7 @@ const int ProcessSignal::s_iFilterGenerationCount = sizeof(s_aszFilterGeneration
 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, SGP* pSGP)
+                              int iGeometry, double dFocalLength, double dSourceDetectorLength, SGP* pSGP)
                               : m_adFourierCosTable(NULL), m_adFourierSinTable(NULL), m_adFilter(NULL), m_fail(false)
 {
   m_idFilterMethod = convertFilterMethodNameToID (szFilterMethodName);
@@ -117,7 +117,8 @@ ProcessSignal::ProcessSignal (const char* szFilterName, const char* szFilterMeth
   }
   
   init (m_idFilter, m_idFilterMethod, dBandwidth, dSignalIncrement, nSignalPoints, dFilterParam, m_idDomain, 
-    m_idFilterGeneration, iZeropad, iPreinterpolationFactor, iTraceLevel, iGeometry, dFocalLength, pSGP);
+    m_idFilterGeneration, iZeropad, iPreinterpolationFactor, iTraceLevel, iGeometry, dFocalLength, 
+    dSourceDetectorLength, pSGP);
 }
 
 
@@ -125,7 +126,7 @@ 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, 
-                     double dFocalLength, SGP* pSGP)
+                     double dFocalLength, double dSourceDetectorLength, SGP* pSGP)
 {
   int i;
   m_idFilter = idFilter;
@@ -134,6 +135,7 @@ ProcessSignal::init (const int idFilter, const int idFilterMethod, double dBandw
   m_idFilterGeneration = idFilterGeneration;
   m_idGeometry = iGeometry;
   m_dFocalLength = dFocalLength;
+  m_dSourceDetectorLength = dSourceDetectorLength;
   
   if (m_idFilter == SignalFilter::FILTER_INVALID || m_idDomain == SignalFilter::DOMAIN_INVALID || m_idFilterMethod == FILTER_METHOD_INVALID || m_idFilterGeneration == FILTER_GENERATION_INVALID) {
     m_fail = true;
@@ -149,12 +151,12 @@ 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 rather than 2 times distance to detector, 
+  // scale signalInc/BW to adjust for imaginary detector through origin of phantom 
   // see Kak-Slaney Fig 3.22, for Collinear diagram
   if (m_idGeometry == Scanner::GEOMETRY_EQUILINEAR) {
-    m_dSignalInc /= 2;
-    m_dBandwidth *= 2;
+    double dEquilinearScale = m_dSourceDetectorLength / m_dFocalLength;
+    m_dSignalInc /= dEquilinearScale;
+    m_dBandwidth *= dEquilinearScale;
   }
   
   if (m_idFilterMethod == FILTER_METHOD_FFT) {