r11237: Oct 18, 2006 Version 4.5.1

[ctsim.git] / libctsim / backprojectors.cpp

diff --git a/libctsim/backprojectors.cpp b/libctsim/backprojectors.cpp
index d38b7189f6b6c878b09ec0549dca5daf242ce24e..2d0d60cc718263746866659b727ba5ed7b28feeb 100644 (file)
--- a/libctsim/backprojectors.cpp
+++ b/libctsim/backprojectors.cpp
@@ -270,12 +270,11 @@ Backproject::Backproject (const Projections& proj, ImageFile& im, int interpType
   detInc = proj.detInc();
   nDet = proj.nDet();
   iDetCenter = (nDet - 1) / 2; // index refering to L=0 projection 
-  rotScale = proj.rotInc();
   
   if (proj.geometry() == Scanner::GEOMETRY_PARALLEL)
-    rotScale /= (proj.nView() * proj.rotInc() / PI); // scale by number of PI rotations
+    rotScale = PI / proj.nView(); // scale by number of PI rotations
   else if (proj.geometry() == Scanner::GEOMETRY_EQUIANGULAR || proj.geometry() == Scanner::GEOMETRY_EQUILINEAR)
-    rotScale /= (proj.nView() * proj.rotInc() / (2 * PI)); // scale by number of 2PI rotations
+    rotScale =  (2 * PI) / proj.nView(); // scale by number of 2PI rotations
   else
     sys_error (ERR_SEVERE, "Invalid geometry type %d [Backproject::Backproject]", proj.geometry());
   
@@ -588,7 +587,7 @@ BackprojectIntDiff::BackprojectView (const double* const filteredProj, const dou
 #elif SIZEOF_LONG == 8
   static const int scaleShift = 32;
 #endif
-  static const long scale = (1 << scaleShift);
+  static const long scale = (1L << scaleShift);
   static const long scaleBitmask = scale - 1;
   static const long halfScale = scale / 2;
   static const double dInvScale = 1. / scale;
@@ -621,20 +620,26 @@ BackprojectIntDiff::BackprojectView (const double* const filteredProj, const dou
         const int iDetPos = (curDetPos + halfScale) >> scaleShift;
         if (iDetPos >= 0 && iDetPos <= iLastDet)
           *pImCol++ += filteredProj[iDetPos];
+        else
+          pImCol++;
+
       }        // end for iy
     } else if (interpType == Backprojector::INTERP_FREQ_PREINTERPOLATION) {
       for (int iy = 0; iy < ny; iy++, curDetPos += det_dy) {
         const int iDetPos = ((curDetPos + halfScale) >> scaleShift) * m_interpFactor;
         if (iDetPos >= 0 && iDetPos <= iLastDet)
           *pImCol++ += filteredProj[iDetPos];
+        else
+          pImCol++;
       }        // end for iy
     } else if (interpType == Backprojector::INTERP_LINEAR) {
       for (int iy = 0; iy < ny; iy++, curDetPos += det_dy) {
         const long iDetPos = curDetPos >> scaleShift;
-        const long detRemainder = curDetPos & scaleBitmask;
-        if (iDetPos >= 0 && iDetPos <= iLastDet)
-           *pImCol++ += filteredProj[iDetPos] + (detRemainder * deltaFilteredProj[iDetPos]);
-           
+        if (iDetPos >= 0 && iDetPos <= iLastDet) {
+         const long detRemainder = curDetPos & scaleBitmask;
+         *pImCol++ += filteredProj[iDetPos] + (detRemainder * deltaFilteredProj[iDetPos]);
+       } else
+          pImCol++;
       }        // end for iy
     } else if (interpType == Backprojector::INTERP_CUBIC) {
       for (int iy = 0; iy < ny; iy++, curDetPos += det_dy) {