//---------------------------------------------------------------------------------------
// Initialize Data Projectors - private
void CForwardProjectionAlgorithm::_init()
{
// forward projection data projector
m_pForwardProjector = dispatchDataProjector(
m_pProjector,
SinogramMaskPolicy(m_pSinogramMask), // sinogram mask
ReconstructionMaskPolicy(m_pVolumeMask), // reconstruction mask
DefaultFPPolicy(m_pVolume, m_pSinogram), // forward projection
m_bUseSinogramMask, m_bUseVolumeMask, true // options on/off
);
}
//----------------------------------------------------------------------------------------
// Iterate
void CCglsAlgorithm::run(int _iNrIterations)
{
// check initialized
ASTRA_ASSERT(m_bIsInitialized);
// data projectors
CDataProjectorInterface* pForwardProjector;
CDataProjectorInterface* pFirstForwardProjector;
CDataProjectorInterface* pBackProjector;
// Clear reconstruction volume.
if (m_bClearReconstruction) {
m_pReconstruction->setData(0.0f);
}
// forward projection data projector
if (m_bUseJacobiPreconditioner) {
// w = A t
pForwardProjector = dispatchDataProjector(
m_pProjector,
SinogramMaskPolicy(m_pSinogramMask), // sinogram mask
ReconstructionMaskPolicy(m_pReconstructionMask), // reconstruction mask
DefaultFPPolicy(t, w), // forward projection
m_bUseSinogramMask, m_bUseReconstructionMask, true // options on/off
);
} else {
// w = A p
pForwardProjector = dispatchDataProjector(
m_pProjector,
SinogramMaskPolicy(m_pSinogramMask), // sinogram mask
ReconstructionMaskPolicy(m_pReconstructionMask), // reconstruction mask
DefaultFPPolicy(p, w), // forward projection
m_bUseSinogramMask, m_bUseReconstructionMask, true // options on/off
);
}
// backprojection data projector
pBackProjector = dispatchDataProjector(
m_pProjector,
SinogramMaskPolicy(m_pSinogramMask), // sinogram mask
ReconstructionMaskPolicy(m_pReconstructionMask), // reconstruction mask
DefaultBPPolicy(z, r), // backprojection
m_bUseSinogramMask, m_bUseReconstructionMask, true // options on/off
);
// First forward projector to compute the Jacobi preconditioner, which
// is just the norm squares of the columns of the projection matrix A
// (it is diagonal of A' * A)
pFirstForwardProjector = dispatchDataProjector(
m_pProjector,
SinogramMaskPolicy(m_pSinogramMask), // sinogram mask
ReconstructionMaskPolicy(m_pReconstructionMask), // reconstruction mask
TotalPixelWeightPolicy(c, false, true), // forward projection
m_bUseSinogramMask, m_bUseReconstructionMask, true // options on/off
);
// Compute the Jacobi preconditioner.
if (m_bUseJacobiPreconditioner) {
c->setData(0.f);
pFirstForwardProjector->project();
// Compute sqrt
c->sqrt();
}
int i;
if (m_iIteration == 0) {
// r = b;
r->copyData(m_pSinogram->getData());
// w = A*x0
p->copyData(m_pReconstruction->getData());
pForwardProjector->project();
// r = b - A*x0
*r -= *w;
// z = A' * (b - A * x0) = A' * r
z->setData(0.0f);
pBackProjector->project();
// CHECK
//if (m_bUseMinConstraint)
// z->clampMin(m_fMinValue);
//if (m_bUseMaxConstraint)
// z->clampMax(m_fMaxValue);
// Precondition?
if (m_bUseJacobiPreconditioner) {
*z /= *c;
}
// p = z;
p->copyData(z->getData());
// gamma = dot(z,z);
gamma = 0.0f;
for (i = 0; i < z->getSize(); ++i) {
gamma += z->getData()[i] * z->getData()[i];
}
m_iIteration++;
}
// start iterations
//for (int iIteration = _iNrIterations-1; iIteration >= 0; --iIteration) {
for (int iIteration = 0; iIteration < _iNrIterations; ++iIteration) {
// start timer
m_ulTimer = CPlatformDepSystemCode::getMSCount();
if (m_bUseJacobiPreconditioner) {
// t = C^-1 p
t->copyData(p->getData());
*t /= *c;
}
// w = A*p (or A*t if precondioning)
w->setData(0);
pForwardProjector->project();
// alpha = gamma/dot(w,w);
float32 tmp = 0;
for (i = 0; i < w->getSize(); ++i) {
tmp += w->getData()[i] * w->getData()[i];
}
alpha = gamma / tmp;
if (m_bUseJacobiPreconditioner) {
// x = x + alpha*t;
for (i = 0; i < m_pReconstruction->getSize(); ++i) {
m_pReconstruction->getData()[i] += alpha * t->getData()[i];
}
} else {
// x = x + alpha*p;
for (i = 0; i < m_pReconstruction->getSize(); ++i) {
m_pReconstruction->getData()[i] += alpha * p->getData()[i];
}
}
// r = r - alpha*w;
for (i = 0; i < r->getSize(); ++i) {
r->getData()[i] -= alpha * w->getData()[i];
}
// z = A'*r;
z->setData(0.0f);
pBackProjector->project();
// Precondition?
if (m_bUseJacobiPreconditioner) {
// z = C^-1 C
*z /= *c;
}
// CHECKME: should these be here?
// This was z. CHECK
if (m_bUseMinConstraint)
m_pReconstruction->clampMin(m_fMinValue);
if (m_bUseMaxConstraint)
m_pReconstruction->clampMax(m_fMaxValue);
// beta = 1/gamma;
beta = 1.0f / gamma;
// gamma = dot(z,z);
gamma = 0;
for (i = 0; i < z->getSize(); ++i) {
gamma += z->getData()[i] * z->getData()[i];
}
// beta = gamma*beta;
beta *= gamma;
// p = z + beta*p;
for (i = 0; i < z->getSize(); ++i) {
p->getData()[i] = z->getData()[i] + beta * p->getData()[i];
}
// end timer
m_ulTimer = CPlatformDepSystemCode::getMSCount() - m_ulTimer;
// Compute metrics.
computeIterationMetrics(iIteration, _iNrIterations, r);
m_iIteration++;
}
ASTRA_DELETE(pForwardProjector);
ASTRA_DELETE(pBackProjector);
ASTRA_DELETE(pFirstForwardProjector);
//if (m_iIteration == 0) {
// // r = b;
// r->copyData(m_pSinogram->getData());
// // z = A'*b;
// z->setData(0.0f);
// pBackProjector->project();
// // CHECK
// //if (m_bUseMinConstraint)
// // z->clampMin(m_fMinValue);
// //if (m_bUseMaxConstraint)
// // z->clampMax(m_fMaxValue);
// // p = z;
// p->copyData(z->getData());
// // gamma = dot(z,z);
// gamma = 0.0f;
// for (i = 0; i < z->getSize(); ++i) {
// gamma += z->getData()[i] * z->getData()[i];
// }
//
// m_iIteration++;
//}
//// start iterations
////for (int iIteration = _iNrIterations-1; iIteration >= 0; --iIteration) {
//for (int iIteration = 0; iIteration < _iNrIterations; ++iIteration) {
// // start timer
// m_ulTimer = CPlatformDepSystemCode::getMSCount();
//
// // w = A*p;
// pForwardProjector->project();
//
// // alpha = gamma/dot(w,w);
// float32 tmp = 0;
// for (i = 0; i < w->getSize(); ++i) {
// tmp += w->getData()[i] * w->getData()[i];
// }
// alpha = gamma / tmp;
// // x = x + alpha*p;
// for (i = 0; i < m_pReconstruction->getSize(); ++i) {
// m_pReconstruction->getData()[i] += alpha * p->getData()[i];
// }
// // r = r - alpha*w;
// for (i = 0; i < r->getSize(); ++i) {
// r->getData()[i] -= alpha * w->getData()[i];
// }
// // z = A'*r;
// z->setData(0.0f);
// pBackProjector->project();
// // CHECKME: should these be here?
// // This was z. CHECK
// if (m_bUseMinConstraint)
// m_pReconstruction->clampMin(m_fMinValue);
// if (m_bUseMaxConstraint)
// m_pReconstruction->clampMax(m_fMaxValue);
// // beta = 1/gamma;
// beta = 1.0f / gamma;
// // gamma = dot(z,z);
// gamma = 0;
// for (i = 0; i < z->getSize(); ++i) {
// gamma += z->getData()[i] * z->getData()[i];
// }
// // beta = gamma*beta;
// beta *= gamma;
// // p = z + beta*p;
// for (i = 0; i < z->getSize(); ++i) {
// p->getData()[i] = z->getData()[i] + beta * p->getData()[i];
// }
//
// // end timer
// m_ulTotalTime += CPlatformDepSystemCode::getMSCount() - m_ulTimer;
// // Compute metrics.
// computeIterationMetrics(iIteration, _iNrIterations);
// m_iIteration++;
//}
}
