src/snark/art_bkproj.cpp

   1 /*
   2  ***********************************************************
   3  $SNARK_Header: S N A R K  1 4 - A PICTURE RECONSTRUCTION PROGRAM $
   4  $HeadURL: svn://dig.cs.gc.cuny.edu/snark/trunk/src/snark/art_bkproj.cpp $
   5  $LastChangedRevision: 85 $
   6  $Date: 2014-07-02 16:07:08 -0400 (Wed, 02 Jul 2014) $
   7  $Author: agulati $
   8  ***********************************************************
   9
  10  CALCULATE BACKPROJECTIONS
  11  */
  12
  13 #include <cstdio>
  14 #include <cmath>
  15
  16 #include "blkdta.h"
  17 #include "uiod.h"
  18 #include "geom.h"
  19
  20 #ifdef FFCOMPARE
  21 #include "geom.h"
  22 #endif
  23
  24 #include "art.h"
  25
  26 void art_class::bkproj(REAL* recon, REAL diff,REAL abdiff,REAL* ibase, INTEGER np, INTEGER nr, INTEGER* list, REAL* weight, INTEGER numb, REAL snorm)
  27 {
  28         REAL change;
  29         REAL dual; //wei, bug 266
  30         REAL a;
  31         REAL b;
  32         REAL factor;
  33
  34
  35         if (ArtIn.bayef)
  36         {
  37                 // BAYESIAN
  38                 //index = indexd(np, nr); //Ran, bug 266
  39                 dual = ArtIn.totalRays[np * GeoPar.nrays + nr];
  40                 change = diff - dual;  //wei, bug 266
  41                 snorm = (REAL) 1.0 + snorm * ArtIn.snr2;
  42         }
  43         else if (ArtIn.art4f)
  44         {
  45                 // ART4
  46                 // index = indexd(np, nr); //Ran, bug 266
  47                 dual = ArtIn.totalRays[np * GeoPar.nrays + nr]; //wei, bug 266
  48                 a = diff + ArtIn.toler;
  49                 b = diff - ArtIn.toler;
  50
  51                 change = MAX0(MIN0(a, dual), b);
  52                 ArtIn.totalRays[np * GeoPar.nrays + nr] -= change * ArtIn.relax; //wei, bug 266
  53         }
  54
  55         // ART3
  56         else
  57         {
  58                 if (abdiff <= ArtIn.toler)
  59                 {
  60                         return;
  61                 }
  62
  63                 if (abdiff >= ArtIn.toler + ArtIn.toler)
  64                 {
  65                         change = diff;
  66                 }
  67                 else
  68                 {
  69                         // REFLECTION
  70                         if (diff < 0)
  71                                 change = (REAL) 2.0 * (diff + ArtIn.toler); //  -2*toler < diff <-toler
  72                         else
  73                                 change = (REAL) 2.0 * (diff - ArtIn.toler); //  toler < diff < 2* toler      by wei, 8/2005
  74                 }
  75         }
  76         // ADJUST RECONSTRUCTED PICTURE
  77
  78         factor = ArtIn.relax * change / snorm;
  79
  80 #ifdef FFCOMPARE
  81
  82 #endif
  83
  84         if (ArtIn.bayef)
  85         {
  86                 ArtIn.totalRays[np * GeoPar.nrays + nr] += factor;  //wei, bug 266
  87                 factor *= ArtIn.snr2;
  88         }
  89
  90         ////////// dump recon ////////////
  91 #ifdef FFCOMPARE
  92
  93 #endif
  94         //////////////////////////////////
  95
  96
  97         artbck(recon, factor, list, weight, numb, ArtIn.thrlo, ArtIn.thrup,
  98                         ArtIn.cr, ArtIn.bartf, ArtIn.halfwy, ArtIn.thtol, ArtIn.art2f);
  99
 100         return;
 101 }
 102