X-Git-Url: http://git.kpe.io/?p=ctsim.git;a=blobdiff_plain;f=libctsim%2Ffilter.cpp;h=3a0e1c799aad5d156e402653b0050b933890d51a;hp=b2d3062c7dbe17934f1e78d4dbf6ceb55d6a0998;hb=a5139613f6b92aeb8db9daa87f021c78d17d82a5;hpb=44ba9ce559d2d52cbd7bbea6bcd76242840fd3eb

diff --git a/libctsim/filter.cpp b/libctsim/filter.cpp
index b2d3062..3a0e1c7 100644
--- a/libctsim/filter.cpp
+++ b/libctsim/filter.cpp
@@ -1,5 +1,5 @@
 /*****************************************************************************
-** FILE IDENTIFICATION
+** File IDENTIFICATION
 ** 
 **     Name:                   filter.cpp
 **     Purpose:                Routines for signal-procesing filters
@@ -9,7 +9,7 @@
 **  This is part of the CTSim program
 **  Copyright (C) 1983-2000 Kevin Rosenberg
 **
-**  $Id: filter.cpp,v 1.2 2000/06/20 17:54:51 kevin Exp $
+**  $Id: filter.cpp,v 1.27 2000/08/22 16:49:56 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
@@ -27,65 +27,306 @@
 
 #include "ct.h"
 
+int SignalFilter::N_INTEGRAL=500;  //static member
+
+const int SignalFilter::FILTER_INVALID = -1 ;
+const int SignalFilter::FILTER_ABS_BANDLIMIT = 0; 	// filter times |x = |
+const int SignalFilter::FILTER_ABS_G_HAMMING = 1;
+const int SignalFilter::FILTER_ABS_COSINE = 2;
+const int SignalFilter::FILTER_ABS_SINC = 3;
+const int SignalFilter::FILTER_SHEPP = 4;
+const int SignalFilter::FILTER_BANDLIMIT = 5;
+const int SignalFilter::FILTER_SINC = 6;
+const int SignalFilter::FILTER_G_HAMMING = 7;
+const int SignalFilter::FILTER_COSINE = 8;
+const int SignalFilter::FILTER_TRIANGLE = 9;
+
+const char* SignalFilter::s_aszFilterName[] = {
+  {"abs_bandlimit"},
+  {"abs_hamming"},
+  {"abs_cosine"},
+  {"abs_sinc"},
+  {"shepp"},
+  {"bandlimit"},
+  {"sinc"},
+  {"hamming"},
+  {"cosine"},
+  {"triangle"},
+};
+
+const char* SignalFilter::s_aszFilterTitle[] = {
+  {"Abs(w) * Bandlimit"},
+  {"Abs(w) * Hamming"},
+  {"Abs(w) * Cosine"},
+  {"Abs(w) * Sinc"},
+  {"Shepp"},
+  {"Bandlimit"},
+  {"Sinc"},
+  {"Hamming"},
+  {"Cosine"},
+  {"Triangle"},
+};
+
+const int SignalFilter::s_iFilterCount = sizeof(s_aszFilterName) / sizeof(const char*);
+
+
+const int SignalFilter::DOMAIN_INVALID = -1;
+const int SignalFilter::DOMAIN_FREQUENCY = 0;
+const int SignalFilter::DOMAIN_SPATIAL = 1;
+    
+const char* SignalFilter::s_aszDomainName[] = {
+  {"frequency"},
+  {"spatial"},
+};
+
+const char* SignalFilter::s_aszDomainTitle[] = {
+  {"Frequency"},
+  {"Spatial"},
+};
+
+const int SignalFilter::s_iDomainCount = sizeof(s_aszDomainName) / sizeof(const char*);
+
 
 /* NAME
- *   filter_generate				Generate a filter
+ *   SignalFilter::SignalFilter     Construct a signal
  *
  * SYNOPSIS
- *   f = filter_generate (filt_type, bw, xmin, xmax, n, param, domain, analytic)
- *   double f				Generated filter vector
- *   int filt_type			Type of filter wanted
- *   double bw				Bandwidth of filter
- *   double xmin, xmax			Filter limits
- *   int n				Number of points in filter
- *   double param			General input parameter to filters
- *   int domain				FREQ or SPATIAL domain wanted
- *   int numint				Number if intervals for calculating
- *					discrete inverse fourier xform
- *					for spatial domain filters.  For
- *					ANALYTIC solutions, use numint = 0
+ *   f = SignalFilter (filt_type, bw, filterMin, filterMax, n, param, domain, analytic)
+ *   double f		Generated filter vector
+ *   int filt_type	Type of filter wanted
+ *   double bw		Bandwidth of filter
+ *   double filterMin, filterMax	Filter limits
+ *   int nFilterPoints	Number of points in signal
+ *   double param	General input parameter to filters
+ *   int domain		FREQUENCY or SPATIAL domain wanted
  */
 
-SignalFilter::SignalFilter (const FilterType filt_type, double bw, double xmin, double xmax, int n, double param, const DomainType domain, int numint)
+SignalFilter::SignalFilter (const char* szFilterName, double dFilterMinimum, double dFilterMaximum, int nFilterPoints, double dBandwidth, double dFilterParam, const char* szDomainName)
+  : m_adFilter(NULL), m_fail(false)
+{
+  m_idFilter = convertFilterNameToID (szFilterName);
+  if (m_idFilter == FILTER_INVALID) {
+    m_fail = true;
+    m_failMessage = "Invalid Filter name ";
+    m_failMessage += szFilterName;
+    return;
+  }
+  m_idDomain = convertDomainNameToID (szDomainName);
+  if (m_idDomain == DOMAIN_INVALID) {
+    m_fail = true;
+    m_failMessage = "Invalid domain name ";
+    m_failMessage += szDomainName;
+    return;
+  }
+  init (m_idFilter, dFilterMinimum, dFilterMaximum, nFilterPoints, dBandwidth, dFilterParam, m_idDomain);
+}
+
+SignalFilter::SignalFilter (const int idFilter, double dFilterMinimum, double dFilterMaximum, int nFilterPoints, double dBandwidth, double dFilterParam, const int idDomain)
+  : m_adFilter(NULL), m_fail(false)
 {
-  m_vecFilter = new double [n];
-  m_filterType = filt_type;
-  m_bw = bw;
+  init (idFilter, dFilterMinimum, dFilterMaximum, nFilterPoints, dBandwidth, dFilterParam, idDomain);
+}
 
-  double xinc = (xmax - xmin) / (n - 1);
+SignalFilter::SignalFilter (const char* szFilterName, const char* szDomainName, double dBandwidth, double dFilterParam)
+  : m_adFilter(NULL), m_fail(false)
+{
+  m_nFilterPoints = 0;
+  m_dBandwidth = dBandwidth;
+  m_dFilterParam = dFilterParam;  
+  m_idFilter = convertFilterNameToID (szFilterName);
+  if (m_idFilter == FILTER_INVALID) {
+    m_fail = true;
+    m_failMessage = "Invalid Filter name ";
+    m_failMessage += szFilterName;
+    return;
+  }
+  m_idDomain = convertDomainNameToID (szDomainName);
+  if (m_idDomain == DOMAIN_INVALID) {
+    m_fail = true;
+    m_failMessage = "Invalid domain name ";
+    m_failMessage += szDomainName;
+    return;
+  }
+}
 
-  if (m_filterType == FILTER_SHEPP) {
-    double a = 2 * m_bw;
+void
+SignalFilter::init (const int idFilter, double dFilterMinimum, double dFilterMaximum, int nFilterPoints, double dBandwidth, double dFilterParam, const int idDomain)
+{
+  m_idFilter = idFilter;
+  m_idDomain = idDomain;
+  if (m_idFilter == FILTER_INVALID || m_idDomain == DOMAIN_INVALID) {
+    m_fail = true;
+    return;
+  }
+  if (nFilterPoints < 2) {
+    m_fail = true;
+    m_failMessage = "Number of filter points ";
+    m_failMessage += nFilterPoints;
+    m_failMessage = " less than 2";
+    return;
+  }
+
+  m_nameFilter = convertFilterIDToName (m_idFilter);
+  m_nameDomain = convertDomainIDToName (m_idDomain);
+  m_nFilterPoints = nFilterPoints;
+  m_dFilterParam = dFilterParam;  
+  m_dBandwidth = dBandwidth;
+  m_dFilterMin = dFilterMinimum;
+  m_dFilterMax = dFilterMaximum;
+
+  m_dFilterInc = (m_dFilterMax - m_dFilterMin) / (m_nFilterPoints - 1);
+  m_adFilter = new double [m_nFilterPoints];
+
+  if (m_idDomain == DOMAIN_FREQUENCY)
+      createFrequencyFilter (m_adFilter);
+  else if (m_idDomain == DOMAIN_SPATIAL)
+      createSpatialFilter (m_adFilter);
+}
+
+
+SignalFilter::~SignalFilter (void)
+{
+    delete [] m_adFilter;
+}
+
+void
+SignalFilter::createFrequencyFilter (double* adFilter) const
+{
+  double x;
+  int i;
+  for (x = m_dFilterMin, i = 0; i < m_nFilterPoints; x += m_dFilterInc, i++)
+    adFilter[i] = frequencyResponse (x);
+}
+
+
+void
+SignalFilter::createSpatialFilter (double* adFilter) const
+{
+  if (m_idFilter == FILTER_SHEPP) {
+    double a = 2 * m_dBandwidth;
     double c = - 4. / (a * a);
-    int center = (n - 1) / 2;
+    int center = (m_nFilterPoints - 1) / 2;
     int sidelen = center;
-    m_vecFilter[center] = 4. / (a * a);
-    
+    m_adFilter[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 (domain == D_FREQ) {
-    double x;
-    int i;
-    for (x = xmin, i = 0; i < n; x += xinc, i++)
-      m_vecFilter[i] = frequencyResponse (x, param);
-  } else if (domain == D_SPATIAL) {
-    double x;
-    int i;
-    for (x = xmin, i = 0; i < n; x += xinc, i++)
-      if (numint == 0)
-	m_vecFilter[i] = spatialResponseAnalytic (x, param);
-      else
-	m_vecFilter[i] = spatialResponseCalc (x, param, numint);
+      m_adFilter [center + i] = m_adFilter [center - i] = c / (4 * (i * i) - 1);
   } else {
-    sys_error (ERR_WARNING, "Illegal domain %d [filt_generate]", domain);
+    double x = m_dFilterMin;
+    for (int i = 0; i < m_nFilterPoints; i++, x += m_dFilterInc) {
+      if (haveAnalyticSpatial(m_idFilter))
+	m_adFilter[i] = spatialResponseAnalytic (x);
+      else
+	m_adFilter[i] = spatialResponseCalc (x);
+    }
   }
 }
 
-SignalFilter::~SignalFilter (void)
+int
+SignalFilter::convertFilterNameToID (const char *filterName)
+{
+  int filterID = FILTER_INVALID;
+
+  for (int i = 0; i < s_iFilterCount; i++)
+    if (strcasecmp (filterName, s_aszFilterName[i]) == 0) {
+      filterID = i;
+      break;
+    }
+
+  return (filterID);
+}
+
+const char *
+SignalFilter::convertFilterIDToName (const int filterID)
+{
+  static const char *name = "";
+ 
+  if (filterID >= 0 && filterID < s_iFilterCount)
+      return (s_aszFilterName [filterID]);
+
+  return (name);
+}
+
+const char *
+SignalFilter::convertFilterIDToTitle (const int filterID)
+{
+  static const char *title = "";
+ 
+  if (filterID >= 0 && filterID < s_iFilterCount)
+      return (s_aszFilterTitle [filterID]);
+
+  return (title);
+}
+      
+int
+SignalFilter::convertDomainNameToID (const char* const domainName)
+{
+  int dID = DOMAIN_INVALID;
+
+  for (int i = 0; i < s_iDomainCount; i++)
+   if (strcasecmp (domainName, s_aszDomainName[i]) == 0) {
+      dID = i;
+      break;
+    }
+
+  return (dID);
+}
+
+const char *
+SignalFilter::convertDomainIDToName (const int domainID)
+{
+  static const char *name = "";
+
+  if (domainID >= 0 && domainID < s_iDomainCount)
+      return (s_aszDomainName [domainID]);
+
+  return (name);
+}
+
+const char *
+SignalFilter::convertDomainIDToTitle (const int domainID)
+{
+  static const char *title = "";
+
+  if (domainID >= 0 && domainID < s_iDomainCount)
+      return (s_aszDomainTitle [domainID]);
+
+  return (title);
+}
+
+
+double
+SignalFilter::response (double x)
+{
+  double response = 0;
+
+  if (m_idDomain == DOMAIN_SPATIAL)
+    response = spatialResponse (m_idFilter, m_dBandwidth, x, m_dFilterParam);
+  else if (m_idDomain == DOMAIN_FREQUENCY)
+    response = frequencyResponse (m_idFilter, m_dBandwidth, x, m_dFilterParam);
+
+  return (response);
+}
+
+
+double 
+SignalFilter::spatialResponse (int filterID, double bw, double x, double param)
 {
-  delete m_vecFilter;
+  if (haveAnalyticSpatial(filterID))
+    return spatialResponseAnalytic (filterID, bw, x, param);
+  else
+    return spatialResponseCalc (filterID, bw, x, param, N_INTEGRAL);
 }
 
+void
+SignalFilter::copyFilterData (double* pdFilter, const int iStart, const int nPoints) const
+{
+    int iFirst = clamp (iStart, 0, m_nFilterPoints - 1);
+    int iLast = clamp (iFirst + nPoints - 1, 0, m_nFilterPoints - 1);
+
+    for (int i = iFirst; i <= iLast; i++)
+	pdFilter[i - iFirst] = m_adFilter[i];
+}
 
 /* NAME
  *   filter_spatial_response_calc	Calculate filter by discrete inverse fourier
@@ -103,17 +344,17 @@ SignalFilter::~SignalFilter (void)
  */
 
 double 
-SignalFilter::spatialResponseCalc (double x, double param, int n) const
+SignalFilter::spatialResponseCalc (double x) const
 {
-  return (spatialResponseCalc (m_filterType, m_bw, x, param, n));
+  return (spatialResponseCalc (m_idFilter, m_dBandwidth, x, m_dFilterParam, N_INTEGRAL));
 }
 
 double 
-SignalFilter::spatialResponseCalc (FilterType fType, double bw, double x, double param, int n)
+SignalFilter::spatialResponseCalc (int filterID, double bw, double x, double param, int n)
 {
   double zmin, zmax;
 
-  if (fType == FILTER_TRIANGLE) {
+  if (filterID == FILTER_TRIANGLE) {
     zmin = 0;
     zmax = bw;
   } else {
@@ -125,7 +366,7 @@ SignalFilter::spatialResponseCalc (FilterType fType, double bw, double x, double
   double z = zmin;
   double q [n];
   for (int i = 0; i < n; i++, z += zinc)
-    q[i] = frequencyResponse (fType, bw, z, param) * cos (TWOPI * z * x);
+    q[i] = frequencyResponse (filterID, bw, z, param) * cos (TWOPI * z * x);
   
   double y = 2 * integrateSimpson (zmin, zmax, q, n);
   
@@ -146,45 +387,45 @@ SignalFilter::spatialResponseCalc (FilterType fType, double bw, double x, double
  */
 
 double 
-SignalFilter::frequencyResponse (double u, double param) const
+SignalFilter::frequencyResponse (double u) const
 {
-  return frequencyResponse (m_filterType, m_bw, u, param);
+  return frequencyResponse (m_idFilter, m_dBandwidth, u, m_dFilterParam);
 }
 
 
 double 
-SignalFilter::frequencyResponse (FilterType fType, double bw, double u, double param)
+SignalFilter::frequencyResponse (int filterID, double bw, double u, double param)
 {
   double q;
   double au = fabs (u);
 
-  switch (fType) {
+  switch (filterID) {
   case FILTER_BANDLIMIT:
-    if (au >= bw / 2)
+    if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
       q = 0.;
     else
       q = 1;
     break;
   case FILTER_ABS_BANDLIMIT:
-    if (au >= bw / 2)
+    if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
       q = 0.;
     else
       q = au;
     break;
   case FILTER_TRIANGLE:
-    if (au >= bw)
+    if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
       q = 0;
     else
       q = 1 - au / bw;
     break;
   case FILTER_COSINE:
-    if (au >= bw / 2)
+    if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
       q = 0;
     else
       q = cos(PI * u / bw);
     break;
   case FILTER_ABS_COSINE:
-    if (au >= bw / 2)
+    if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
       q = 0;
     else
       q = au * cos(PI * u / bw);
@@ -196,20 +437,20 @@ SignalFilter::frequencyResponse (FilterType fType, double bw, double u, double p
     q = au * bw * sinc (PI * bw * u, 1.);
     break;
   case FILTER_G_HAMMING:
-    if (au >= bw / 2)
+    if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
       q = 0;
     else
       q = param + (1 - param) * cos (TWOPI * u / bw);
     break;
   case FILTER_ABS_G_HAMMING:
-    if (au >= bw / 2)
+    if (fabs(au) >= fabs(bw / 2) + F_EPSILON)
       q = 0;
     else
       q = au * (param + (1 - param) * cos(TWOPI * u / bw));
     break;
   default:
     q = 0;
-    sys_error (ERR_WARNING, "Frequency response for filter %d not implemented [filter_frequency_response]", fType);
+    sys_error (ERR_WARNING, "Frequency response for filter %d not implemented [filter_frequency_response]", filterID);
     break;
   }
   return (q);
@@ -232,13 +473,37 @@ SignalFilter::frequencyResponse (FilterType fType, double bw, double u, double p
  */
 
 double 
-SignalFilter::spatialResponseAnalytic (double x, double param) const
+SignalFilter::spatialResponseAnalytic (double x) const
 {
-  return spatialResponseAnalytic (m_filterType, m_bw, x, param);
+  return spatialResponseAnalytic (m_idFilter, m_dBandwidth, x, m_dFilterParam);
+}
+
+const bool
+SignalFilter::haveAnalyticSpatial (int filterID)
+{
+  bool haveAnalytic = false;
+
+  switch (filterID) {
+  case FILTER_BANDLIMIT:
+  case FILTER_TRIANGLE:
+  case FILTER_COSINE:
+  case FILTER_G_HAMMING:
+  case FILTER_ABS_BANDLIMIT:
+  case FILTER_ABS_COSINE:
+  case FILTER_ABS_G_HAMMING:
+  case FILTER_SHEPP:
+  case FILTER_SINC:
+    haveAnalytic = true;
+    break;
+  default:
+    break;
+  }
+
+  return (haveAnalytic);
 }
 
 double 
-SignalFilter::spatialResponseAnalytic (FilterType fType, double bw, double x, double param)
+SignalFilter::spatialResponseAnalytic (int filterID, double bw, double x, double param)
 {
   double q, temp;
   double u = TWOPI * x;
@@ -246,7 +511,7 @@ SignalFilter::spatialResponseAnalytic (FilterType fType, double bw, double x, do
   double b = PI / bw;
   double b2 = TWOPI / bw;
 
-  switch (fType) {
+  switch (filterID) {
   case FILTER_BANDLIMIT:
     q = bw * sinc(u * w, 1.0);
     break;
@@ -284,7 +549,7 @@ SignalFilter::spatialResponseAnalytic (FilterType fType, double bw, double x, do
     break;
   case FILTER_ABS_SINC:
   default:
-    sys_error (ERR_WARNING, "Analytic filter type %d not implemented [filter_spatial_response_analytic]", fType);
+    sys_error (ERR_WARNING, "Analytic filter type %d not implemented [filter_spatial_response_analytic]", filterID);
     q = 0;
     break;
   }
@@ -319,106 +584,4 @@ SignalFilter::spatialResponseAnalytic (FilterType fType, double bw, double x, do
  *   Returns the value of integral of u*cos(u)*dV for V = 0 to w
  */
 
-double 
-SignalFilter::integral_abscos (double u, double w)
-{
-  if (fabs (u) > F_EPSILON)
-    return (cos(u * w) - 1) / (u * u) + w / u * sin (u * w);
-  else
-    return (w * w / 2);
-}
-
-
-/* NAME
- *    convolve			Discrete convolution of two functions
- *
- * SYNOPSIS
- *    r = convolve (f1, f2, dx, n, np, func_type)
- *    double r			Convolved result
- *    double f1[], f2[]		Functions to be convolved
- *    double dx			Difference between successive x values
- *    int n			Array index to center convolution about
- *    int np			Number of points in f1 array
- *    int func_type		EVEN or ODD or EVEN_AND_ODD function f2
- *
- * NOTES
- *    f1 is the projection data, its indices range from 0 to np - 1.
- *    The index for f2, the filter, ranges from -(np-1) to (np-1).
- *    There are 3 ways to handle the negative vertices of f2:
- *	1. If we know f2 is an EVEN function, then f2[-n] = f2[n].
- *	   All filters used in reconstruction are even.
- *      2. If we know f2 is an ODD function, then f2[-n] = -f2[n] 
- *      3. If f2 is both ODD AND EVEN, then we must store the value of f2
- *	   for negative indices.  Since f2 must range from -(np-1) to (np-1),
- *	   if we add (np - 1) to f2's array index, then f2's index will
- *	   range from 0 to 2 * (np - 1), and the origin, x = 0, will be
- *	   stored at f2[np-1].
- */
-
-double 
-SignalFilter::convolve (const double func[], const double dx, const int n, const int np, const FunctionSymmetry func_type) const
-{
-  double sum = 0.0;
-
-  if (func_type == FUNC_BOTH) {
-#if UNOPTIMIZED_CONVOLUTION
-    for (int i = 0; i < np; i++)
-      sum += func[i] * m_vecFilter[n - i + (np - 1)];
-#else
-    double* f2 = m_vecFilter + n + (np - 1);
-    for (int i = 0; i < np; i++)
-      sum += *func++ * *f2--;
-#endif
-  }  else if (func_type == FUNC_EVEN) {
-    for (int i = 0; i < np; i++) {
-      int k = abs (n - i);
-      sum += func[i] * m_vecFilter[k];
-    }
-  } else if (func_type == FUNC_ODD) {
-    for (int i = 0; i < np; i++) {
-      int k = n - i;
-      if (k < 0)
-	sum -= func[i] * m_vecFilter[k];
-      else
-	sum += func[i] * m_vecFilter[k];
-    }
-  } else
-    sys_error (ERR_WARNING, "Illegal function type %d [convolve]", func_type);
-
-  return (sum * dx);
-}
-
-
-double 
-SignalFilter::convolve (const float func[], const double dx, const int n, const int np, const FunctionSymmetry func_type) const
-{
-  double sum = 0.0;
-
-  if (func_type == FUNC_BOTH) {
-#if UNOPTIMIZED_CONVOLUTION
-    for (int i = 0; i < np; i++)
-      sum += func[i] * m_vecFilter[n - i + (np - 1)];
-#else
-    double* f2 = m_vecFilter + n + (np - 1);
-    for (int i = 0; i < np; i++)
-      sum += *func++ * *f2--;
-#endif
-  }  else if (func_type == FUNC_EVEN) {
-    for (int i = 0; i < np; i++) {
-      int k = abs (n - i);
-      sum += func[i] * m_vecFilter[k];
-    }
-  } else if (func_type == FUNC_ODD) {
-    for (int i = 0; i < np; i++) {
-      int k = n - i;
-      if (k < 0)
-	sum -= func[i] * m_vecFilter[k];
-      else
-	sum += func[i] * m_vecFilter[k];
-    }
-  } else
-    sys_error (ERR_WARNING, "Illegal function type %d [convolve]", func_type);
-
-  return (sum * dx);
-}