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/*
-----------------------------------------------------------------------
Copyright: 2010-2014, iMinds-Vision Lab, University of Antwerp
2014, 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/>.
-----------------------------------------------------------------------
$Id$
*/
//----------------------------------------------------------------------------------------
// PROJECT ALL
template <typename Policy>
void CParallelBeamBlobKernelProjector2D::project(Policy& p)
{
for (int iAngle = 0; iAngle < m_pProjectionGeometry->getProjectionAngleCount(); ++iAngle) {
for (int iDetector = 0; iDetector < m_pProjectionGeometry->getDetectorCount(); ++iDetector) {
projectSingleRay(iAngle, iDetector, p);
}
}
}
//----------------------------------------------------------------------------------------
// PROJECT SINGLE PROJECTION
template <typename Policy>
void CParallelBeamBlobKernelProjector2D::projectSingleProjection(int _iProjection, Policy& p)
{
for (int iDetector = 0; iDetector < m_pProjectionGeometry->getDetectorCount(); ++iDetector) {
projectSingleRay(_iProjection, iDetector, p);
}
}
//----------------------------------------------------------------------------------------
// PROJECT SINGLE RAY
template <typename Policy>
void CParallelBeamBlobKernelProjector2D::projectSingleRay(int _iProjection, int _iDetector, Policy& p)
{
ASTRA_ASSERT(m_bIsInitialized);
int iRayIndex = _iProjection * m_pProjectionGeometry->getDetectorCount() + _iDetector;
// POLICY: RAY PRIOR
if (!p.rayPrior(iRayIndex)) return;
// get values
float32 t = m_pProjectionGeometry->indexToDetectorOffset(_iDetector);
float32 theta = m_pProjectionGeometry->getProjectionAngle(_iProjection);
if (theta >= 7*PIdiv4) theta -= 2*PI;
bool flip = false;
if (theta >= 3*PIdiv4) {
theta -= PI;
t = -t;
flip = true;
}
if (theta <= PIdiv4) { // -pi/4 <= theta <= pi/4
// precalculate sin, cos, 1/cos
float32 sin_theta = sin(theta);
float32 cos_theta = cos(theta);
float32 inv_cos_theta = 1.0f / cos_theta;
// precalculate other stuff
float32 lengthPerRow = m_pVolumeGeometry->getPixelLengthY() * inv_cos_theta;
float32 updatePerRow = sin_theta * lengthPerRow;
float32 inv_pixelLengthX = 1.0f / m_pVolumeGeometry->getPixelLengthX();
float32 pixelLengthX_over_blobSize = m_pVolumeGeometry->getPixelLengthX() / m_fBlobSize;
// some variables
int row, col, xmin, xmax;
float32 P, x, d;
// calculate P and x for row 0
P = (t - sin_theta * m_pVolumeGeometry->pixelRowToCenterY(0)) * inv_cos_theta;
x = (P - m_pVolumeGeometry->getWindowMinX()) * inv_pixelLengthX - 0.5f;
// for each row
for (row = 0; row < m_pVolumeGeometry->getGridRowCount(); ++row) {
// calculate extent
xmin = (int)ceil((P - m_fBlobSize - m_pVolumeGeometry->getWindowMinX()) * inv_pixelLengthX - 0.5f);
xmax = (int)floor((P + m_fBlobSize - m_pVolumeGeometry->getWindowMinX()) * inv_pixelLengthX - 0.5f);
// add pixels
for (col = xmin; col <= xmax; col++) {
if (col >= 0 && col < m_pVolumeGeometry->getGridColCount()) {
//d = abs(x - col) * pixelLengthX_over_blobSize;
//index = (int)(d*m_iBlobSampleCount+0.5f);
//float32 fWeight = m_pfBlobValues[min(index,m_iBlobSampleCount-1)] * lengthPerRow;
float32 fWeight;
int index;
if ((x >= col) ^ flip) {
d = abs(x - col) * pixelLengthX_over_blobSize * cos_theta;
index = (int)(d*m_iBlobSampleCount+0.5f);
fWeight = m_pfBlobValues[min(index,m_iBlobSampleCount-1)];
} else {
d = abs(x - col) * pixelLengthX_over_blobSize * cos_theta;
index = (int)(d*m_iBlobSampleCount+0.5f);
fWeight = m_pfBlobValuesNeg[min(index,m_iBlobSampleCount-1)];
}
int iVolumeIndex = m_pVolumeGeometry->pixelRowColToIndex(row, col);
// POLICY: PIXEL PRIOR + ADD + POSTERIOR
if (p.pixelPrior(iVolumeIndex)) {
p.addWeight(iRayIndex, iVolumeIndex, fWeight);
p.pixelPosterior(iVolumeIndex);
}
}
}
// update P and x
P += updatePerRow;
x += updatePerRow * inv_pixelLengthX;
}
} else { // pi/4 < theta < 3pi/4
// precalculate sin cos
float32 sin_90_theta = sin(PIdiv2-theta);
float32 cos_90_theta = cos(PIdiv2-theta);
float32 inv_cos_90_theta = 1.0f / cos_90_theta;
// precalculate other stuff
float32 lengthPerCol = m_pVolumeGeometry->getPixelLengthX() * inv_cos_90_theta;
float32 updatePerCol = sin_90_theta * lengthPerCol;
float32 inv_pixelLengthY = 1.0f / m_pVolumeGeometry->getPixelLengthY();
float32 pixelLengthY_over_blobSize = m_pVolumeGeometry->getPixelLengthY() / m_fBlobSize;
// some variables
int row, col, xmin, xmax;
float32 P,x, d;
// calculate P and x for col 0
P = (sin_90_theta * m_pVolumeGeometry->pixelColToCenterX(0) - t) * inv_cos_90_theta;
x = (P - m_pVolumeGeometry->getWindowMinY()) * inv_pixelLengthY - 0.5f;
// for each col
for (col = 0; col < m_pVolumeGeometry->getGridColCount(); ++col) {
// calculate extent
xmin = (int)ceil((P - m_fBlobSize - m_pVolumeGeometry->getWindowMinY()) * inv_pixelLengthY - 0.5f);
xmax = (int)floor((P + m_fBlobSize - m_pVolumeGeometry->getWindowMinY()) * inv_pixelLengthY - 0.5f);
// add pixels
for (row = xmin; row <= xmax; row++) {
if (row >= 0 && row < m_pVolumeGeometry->getGridRowCount()) {
//d = abs(x - row) * pixelLengthY_over_blobSize;
//int index = (int)(d*m_iBlobSampleCount+0.5f);
//float32 fWeight = m_pfBlobValues[min(index,m_iBlobSampleCount-1)] * lengthPerCol;
float32 fWeight;
int index;
if ((x <= row) ^ flip) {
d = abs(x - row) * pixelLengthY_over_blobSize * cos_90_theta;
index = (int)(d*m_iBlobSampleCount+0.5f);
fWeight = m_pfBlobValues[min(index,m_iBlobSampleCount-1)];
} else {
d = abs(x - row) * pixelLengthY_over_blobSize * cos_90_theta;
index = (int)(d*m_iBlobSampleCount+0.5f);
fWeight = m_pfBlobValuesNeg[min(index,m_iBlobSampleCount-1)];
}
int iVolumeIndex = m_pVolumeGeometry->pixelRowColToIndex(row, col);
// POLICY: PIXEL PRIOR + ADD + POSTERIOR
if (p.pixelPrior(iVolumeIndex)) {
p.addWeight(iRayIndex, iVolumeIndex, fWeight);
p.pixelPosterior(iVolumeIndex);
}
}
}
// update P and x
P += updatePerCol;
x += updatePerCol * inv_pixelLengthY;
}
}
// POLICY: RAY POSTERIOR
p.rayPosterior(iRayIndex);
}
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