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/*
-----------------------------------------------------------------------
Copyright: 2010-2015, iMinds-Vision Lab, University of Antwerp
2014-2015, CWI, Amsterdam
Contact: astra@uantwerpen.be
Website: http://sf.net/projects/astra-toolbox
This file is part of the ASTRA Toolbox.
The ASTRA Toolbox is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
The ASTRA Toolbox is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the ASTRA Toolbox. If not, see <http://www.gnu.org/licenses/>.
-----------------------------------------------------------------------
$Id$
*/
template <typename Policy>
void CParallelBeamLinearKernelProjector2D::project(Policy& p)
{
projectBlock_internal(0, m_pProjectionGeometry->getProjectionAngleCount(),
0, m_pProjectionGeometry->getDetectorCount(), p);
}
template <typename Policy>
void CParallelBeamLinearKernelProjector2D::projectSingleProjection(int _iProjection, Policy& p)
{
projectBlock_internal(_iProjection, _iProjection + 1,
0, m_pProjectionGeometry->getDetectorCount(), p);
}
template <typename Policy>
void CParallelBeamLinearKernelProjector2D::projectSingleRay(int _iProjection, int _iDetector, Policy& p)
{
projectBlock_internal(_iProjection, _iProjection + 1,
_iDetector, _iDetector + 1, p);
}
//----------------------------------------------------------------------------------------
// PROJECT BLOCK - vector projection geometry
template <typename Policy>
void CParallelBeamLinearKernelProjector2D::projectBlock_internal(int _iProjFrom, int _iProjTo, int _iDetFrom, int _iDetTo, Policy& p)
{
// get vector geometry
const CParallelVecProjectionGeometry2D* pVecProjectionGeometry;
if (dynamic_cast<CParallelProjectionGeometry2D*>(m_pProjectionGeometry)) {
pVecProjectionGeometry = dynamic_cast<CParallelProjectionGeometry2D*>(m_pProjectionGeometry)->toVectorGeometry();
} else {
pVecProjectionGeometry = dynamic_cast<CParallelVecProjectionGeometry2D*>(m_pProjectionGeometry);
}
// precomputations
const float32 inv_pixelLengthX = 1.0f / m_pVolumeGeometry->getPixelLengthX();
const float32 inv_pixelLengthY = 1.0f / m_pVolumeGeometry->getPixelLengthY();
const int colCount = m_pVolumeGeometry->getGridColCount();
const int rowCount = m_pVolumeGeometry->getGridRowCount();
const int detCount = pVecProjectionGeometry->getDetectorCount();
// loop angles
#pragma omp parallel for
for (int iAngle = _iProjFrom; iAngle < _iProjTo; ++iAngle) {
// variables
float32 detX, detY, x, y, c, r, update_c, update_r, offset;
float32 lengthPerRow, lengthPerCol;
int iVolumeIndex, iRayIndex, row, col, iDetector;
const SParProjection * proj = &pVecProjectionGeometry->getProjectionVectors()[iAngle];
bool vertical = fabs(proj->fRayX) < fabs(proj->fRayY);
if (vertical) {
lengthPerRow = m_pVolumeGeometry->getPixelLengthX() * sqrt(proj->fRayY*proj->fRayY + proj->fRayX*proj->fRayX) / abs(proj->fRayY);
update_c = -m_pVolumeGeometry->getPixelLengthY() * (proj->fRayX/proj->fRayY) * inv_pixelLengthX;
} else {
lengthPerCol = m_pVolumeGeometry->getPixelLengthY() * sqrt(proj->fRayY*proj->fRayY + proj->fRayX*proj->fRayX) / abs(proj->fRayX);
update_r = -m_pVolumeGeometry->getPixelLengthX() * (proj->fRayY/proj->fRayX) * inv_pixelLengthY;
}
// loop detectors
for (iDetector = _iDetFrom; iDetector < _iDetTo; ++iDetector) {
iRayIndex = iAngle * m_pProjectionGeometry->getDetectorCount() + iDetector;
// POLICY: RAY PRIOR
if (!p.rayPrior(iRayIndex)) continue;
detX = proj->fDetSX + (iDetector+0.5f) * proj->fDetUX;
detY = proj->fDetSY + (iDetector+0.5f) * proj->fDetUY;
// vertically
if (vertical) {
// calculate x for row 0
x = detX + (proj->fRayX/proj->fRayY)*(m_pVolumeGeometry->pixelRowToCenterY(0)-detY);
c = (x - m_pVolumeGeometry->getWindowMinX()) * inv_pixelLengthX - 0.5f;
// for each row
for (row = 0; row < rowCount; ++row, c += update_c) {
col = int(c);
offset = c - float32(col);
if (col <= 0 || col >= colCount-1) continue;
iVolumeIndex = row * colCount + col;
// POLICY: PIXEL PRIOR + ADD + POSTERIOR
if (p.pixelPrior(iVolumeIndex)) {
p.addWeight(iRayIndex, iVolumeIndex, (1.0f - offset) * lengthPerRow);
p.pixelPosterior(iVolumeIndex);
}
iVolumeIndex++;
// POLICY: PIXEL PRIOR + ADD + POSTERIOR
if (p.pixelPrior(iVolumeIndex)) {
p.addWeight(iRayIndex, iVolumeIndex, offset * lengthPerRow);
p.pixelPosterior(iVolumeIndex);
}
}
}
// horizontally
else {
// calculate y for col 0
y = detY + (proj->fRayY/proj->fRayX)*(m_pVolumeGeometry->pixelColToCenterX(0)-detX);
r = (m_pVolumeGeometry->getWindowMaxY() - y) * inv_pixelLengthY - 0.5f;
// for each col
for (col = 0; col < colCount; ++col, r += update_r) {
int row = int(r);
offset = r - float32(row);
if (row <= 0 || row >= rowCount-1) continue;
iVolumeIndex = row * colCount + col;
// POLICY: PIXEL PRIOR + ADD + POSTERIOR
if (p.pixelPrior(iVolumeIndex)) {
p.addWeight(iRayIndex, iVolumeIndex, (1.0f - offset) * lengthPerCol);
p.pixelPosterior(iVolumeIndex);
}
iVolumeIndex += colCount;
// POLICY: PIXEL PRIOR + ADD + POSTERIOR
if (p.pixelPrior(iVolumeIndex)) {
p.addWeight(iRayIndex, iVolumeIndex, offset * lengthPerCol);
p.pixelPosterior(iVolumeIndex);
}
}
}
// POLICY: RAY POSTERIOR
p.rayPosterior(iRayIndex);
} // end loop detector
} // end loop angles
}
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