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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 CParallelBeamStripKernelProjector2D::project(Policy& p)
{
projectBlock_internal(0, m_pProjectionGeometry->getProjectionAngleCount(),
0, m_pProjectionGeometry->getDetectorCount(), p);
}
template <typename Policy>
void CParallelBeamStripKernelProjector2D::projectSingleProjection(int _iProjection, Policy& p)
{
projectBlock_internal(_iProjection, _iProjection + 1,
0, m_pProjectionGeometry->getDetectorCount(), p);
}
template <typename Policy>
void CParallelBeamStripKernelProjector2D::projectSingleRay(int _iProjection, int _iDetector, Policy& p)
{
projectBlock_internal(_iProjection, _iProjection + 1,
_iDetector, _iDetector + 1, p);
}
//----------------------------------------------------------------------------------------
// PROJECT BLOCK
template <typename Policy>
void CParallelBeamStripKernelProjector2D::projectBlock_internal(int _iProjFrom, int _iProjTo, int _iDetFrom, int _iDetTo, Policy& p)
{
// variables
float32 detLX, detLY, detRX, detRY, S, T, update_c, update_r, offsetL, offsetR, invTminS;
float32 inv_pixelLengthX, inv_pixelLengthY, pixelArea, res, fRxOverRy, fRyOverRx;
int iVolumeIndex, iRayIndex, iAngle, iDetector;
int row, row_top, row_bottom, col, col_left, col_right, colCount, rowCount, detCount;
const SParProjection * proj = 0;
// 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
inv_pixelLengthX = 1.0f / m_pVolumeGeometry->getPixelLengthX();
inv_pixelLengthY = 1.0f / m_pVolumeGeometry->getPixelLengthY();
pixelArea = m_pVolumeGeometry->getPixelLengthX() * m_pVolumeGeometry->getPixelLengthY();
colCount = m_pVolumeGeometry->getGridColCount();
rowCount = m_pVolumeGeometry->getGridRowCount();
detCount = pVecProjectionGeometry->getDetectorCount();
// loop angles
for (iAngle = _iProjFrom; iAngle < _iProjTo; ++iAngle) {
proj = &pVecProjectionGeometry->getProjectionVectors()[iAngle];
bool vertical = fabs(proj->fRayX) < fabs(proj->fRayY);
if (vertical) {
fRxOverRy = proj->fRayX/proj->fRayY;
update_c = -m_pVolumeGeometry->getPixelLengthY() * fRxOverRy * inv_pixelLengthX;
S = 0.5f - 0.5f*fabs(fRxOverRy);
T = 0.5f + 0.5f*fabs(fRxOverRy);
invTminS = 1.0f / (T-S);
} else {
fRyOverRx = proj->fRayY/proj->fRayX;
update_r = -m_pVolumeGeometry->getPixelLengthX() * fRyOverRx * inv_pixelLengthY;
S = 0.5f - 0.5f*fabs(fRyOverRx);
T = 0.5f + 0.5f*fabs(fRyOverRx);
invTminS = 1.0f / (T-S);
}
// loop detectors
for (iDetector = _iDetFrom; iDetector < _iDetTo; ++iDetector) {
iRayIndex = iAngle * detCount + iDetector;
// POLICY: RAY PRIOR
if (!p.rayPrior(iRayIndex)) continue;
detLX = proj->fDetSX + iDetector * proj->fDetUX;
detLY = proj->fDetSY + iDetector * proj->fDetUY;
detRX = detLX + proj->fDetUX;
detRY = detLY + proj->fDetUY;
// vertically
if (vertical) {
// calculate cL and cR for row 0
float32 xL = detLX + fRxOverRy*(m_pVolumeGeometry->pixelRowToCenterY(0)-detLY);
float32 cL = (xL - m_pVolumeGeometry->getWindowMinX()) * inv_pixelLengthX - 0.5f;
float32 xR = detRX + fRxOverRy*(m_pVolumeGeometry->pixelRowToCenterY(0)-detRY);
float32 cR = (xR - m_pVolumeGeometry->getWindowMinX()) * inv_pixelLengthX - 0.5f;
if (cR < cL) {
float32 tmp = cL;
cL = cR;
cR = tmp;
}
// for each row
for (row = 0; row < rowCount; ++row, cL += update_c, cR += update_c) {
col_left = int(cL-0.5f+S);
col_right = int(cR+1.5-S);
if (col_left < 0) col_left = 0;
if (col_right > colCount-1) col_right = colCount-1;
offsetL = cL - float32(col_left);
offsetR = cR - float32(col_left);
// for each column
for (col = col_left; col <= col_right; ++col, offsetL -= 1.0f, offsetR -= 1.0f) {
iVolumeIndex = row * colCount + col;
// POLICY: PIXEL PRIOR + ADD + POSTERIOR
if (p.pixelPrior(iVolumeIndex)) {
// right ray edge
if (T <= offsetR) res = 1.0f;
else if (S < offsetR) res = 1.0f - 0.5f*(T-offsetR)*(T-offsetR)*invTminS;
else if (-S < offsetR) res = 0.5f + offsetR;
else if (-T < offsetR) res = 0.5f*(offsetR+T)*(offsetR+T)*invTminS;
else res = 0.0f;
// left ray edge
if (T <= offsetL) res -= 1.0f;
else if (S < offsetL) res -= 1.0f - 0.5f*(T-offsetL)*(T-offsetL)*invTminS;
else if (-S < offsetL) res -= 0.5f + offsetL;
else if (-T < offsetL) res -= 0.5f*(offsetL+T)*(offsetL+T)*invTminS;
p.addWeight(iRayIndex, iVolumeIndex, pixelArea*res);
p.pixelPosterior(iVolumeIndex);
}
}
}
}
// horizontally
else {
// calculate rL and rR for row 0
float32 yL = detLY + fRyOverRx*(m_pVolumeGeometry->pixelColToCenterX(0)-detLX);
float32 rL = (m_pVolumeGeometry->getWindowMaxY() - yL) * inv_pixelLengthY - 0.5f;
float32 yR = detRY + fRyOverRx*(m_pVolumeGeometry->pixelColToCenterX(0)-detRX);
float32 rR = (m_pVolumeGeometry->getWindowMaxY() - yR) * inv_pixelLengthY - 0.5f;
if (rR < rL) {
float32 tmp = rL;
rL = rR;
rR = tmp;
}
// for each column
for (col = 0; col < colCount; ++col, rL += update_r, rR += update_r) {
row_top = int(rL-0.5f+S);
row_bottom = int(rR+1.5-S);
if (row_top < 0) row_top = 0;
if (row_bottom > rowCount-1) row_bottom = rowCount-1;
offsetL = rL - float32(row_top);
offsetR = rR - float32(row_top);
// for each row
for (row = row_top; row <= row_bottom; ++row, offsetL -= 1.0f, offsetR -= 1.0f) {
iVolumeIndex = row * colCount + col;
// POLICY: PIXEL PRIOR + ADD + POSTERIOR
if (p.pixelPrior(iVolumeIndex)) {
// right ray edge
if (T <= offsetR) res = 1.0f;
else if (S < offsetR) res = 1.0f - 0.5f*(T-offsetR)*(T-offsetR)*invTminS;
else if (-S < offsetR) res = 0.5f + offsetR;
else if (-T < offsetR) res = 0.5f*(offsetR+T)*(offsetR+T)*invTminS;
else res = 0.0f;
// left ray edge
if (T <= offsetL) res -= 1.0f;
else if (S < offsetL) res -= 1.0f - 0.5f*(T-offsetL)*(T-offsetL)*invTminS;
else if (-S < offsetL) res -= 0.5f + offsetL;
else if (-T < offsetL) res -= 0.5f*(offsetL+T)*(offsetL+T)*invTminS;
p.addWeight(iRayIndex, iVolumeIndex, pixelArea*res);
p.pixelPosterior(iVolumeIndex);
}
}
}
}
// POLICY: RAY POSTERIOR
p.rayPosterior(iRayIndex);
} // end loop detector
} // end loop angles
}
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