Adjust FBP to line integral scaling

3 files changed, 14 insertions, 5 deletions

diff --git a/src/CudaFilteredBackProjectionAlgorithm.cpp b/src/CudaFilteredBackProjectionAlgorithm.cpp
index 88e235b..69140fc 100644
--- a/src/CudaFilteredBackProjectionAlgorithm.cpp
+++ b/src/CudaFilteredBackProjectionAlgorithm.cpp
@@ -151,6 +151,13 @@ void CCudaFilteredBackProjectionAlgorithm::initCUDAAlgorithm()
 	if (!ok) {
 		ASTRA_ERROR("CCudaFilteredBackProjectionAlgorithm: Failed to set short-scan mode");
 	}
+
+	const CVolumeGeometry2D& volGeom = *m_pProjector->getVolumeGeometry();
+	float fPixelArea = volGeom.getPixelArea();
+	ok &= pFBP->setReconstructionScale(1.0f/fPixelArea);
+	if (!ok) {
+		ASTRA_ERROR("CCudaFilteredBackProjectionAlgorithm: Failed to set reconstruction scale");
+	}
 }
 
 
diff --git a/src/CudaReconstructionAlgorithm2D.cpp b/src/CudaReconstructionAlgorithm2D.cpp
index 939a026..6730cea 100644
--- a/src/CudaReconstructionAlgorithm2D.cpp
+++ b/src/CudaReconstructionAlgorithm2D.cpp
@@ -309,9 +309,7 @@ void CCudaReconstructionAlgorithm2D::run(int _iNrIterations)
 		m_bAlgoInit = true;
 	}
 
-	float fSinogramScale = 1.0f;
-
-	ok = m_pAlgo->copyDataToGPU(m_pSinogram->getDataConst(), m_pSinogram->getGeometry()->getDetectorCount(), fSinogramScale,
+	ok = m_pAlgo->copyDataToGPU(m_pSinogram->getDataConst(), m_pSinogram->getGeometry()->getDetectorCount(),
 	                            m_pReconstruction->getDataConst(), volgeom.getGridColCount(),
 	                            m_bUseReconstructionMask ? m_pReconstructionMask->getDataConst() : 0, volgeom.getGridColCount(),
 	                            m_bUseSinogramMask ? m_pSinogramMask->getDataConst() : 0, m_pSinogram->getGeometry()->getDetectorCount());
diff --git a/src/FilteredBackProjectionAlgorithm.cpp b/src/FilteredBackProjectionAlgorithm.cpp
index 423dc6c..95bef3c 100644
--- a/src/FilteredBackProjectionAlgorithm.cpp
+++ b/src/FilteredBackProjectionAlgorithm.cpp
@@ -264,8 +264,12 @@ void CFilteredBackProjectionAlgorithm::run(int _iNrIterations)
 	            DefaultBPPolicy(m_pReconstruction, &filteredSinogram));
 
 	// Scale data
-	int iAngleCount = m_pProjector->getProjectionGeometry()->getProjectionAngleCount();
-	(*m_pReconstruction) *= (PI/2)/iAngleCount;
+	const CVolumeGeometry2D& volGeom = *m_pProjector->getVolumeGeometry();
+	const CProjectionGeometry2D& projGeom = *m_pProjector->getProjectionGeometry();
+
+	int iAngleCount = projGeom.getProjectionAngleCount();
+	float fPixelArea = volGeom.getPixelArea();
+	(*m_pReconstruction) *= PI/(2*iAngleCount*fPixelArea);
 
 	m_pReconstruction->updateStatistics();
 }