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Diffstat (limited to 'src/GeometryUtil2D.cpp')
| -rw-r--r-- | src/GeometryUtil2D.cpp | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/src/GeometryUtil2D.cpp b/src/GeometryUtil2D.cpp new file mode 100644 index 0000000..2ee6185 --- /dev/null +++ b/src/GeometryUtil2D.cpp @@ -0,0 +1,175 @@ +/* +----------------------------------------------------------------------- +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/>. + +----------------------------------------------------------------------- +$Id$ +*/ + +#include "astra/GeometryUtil2D.h" + +#include <cmath> + +namespace astra { + +SParProjection* genParProjections(unsigned int iProjAngles, + unsigned int iProjDets, + double fDetSize, + const float *pfAngles, + const float *pfExtraOffsets) +{ + SParProjection base; + base.fRayX = 0.0f; + base.fRayY = 1.0f; + + base.fDetSX = iProjDets * fDetSize * -0.5f; + base.fDetSY = 0.0f; + + base.fDetUX = fDetSize; + base.fDetUY = 0.0f; + + SParProjection* p = new SParProjection[iProjAngles]; + +#define ROTATE0(name,i,alpha) do { p[i].f##name##X = base.f##name##X * cos(alpha) - base.f##name##Y * sin(alpha); p[i].f##name##Y = base.f##name##X * sin(alpha) + base.f##name##Y * cos(alpha); } while(0) + + for (unsigned int i = 0; i < iProjAngles; ++i) { + if (pfExtraOffsets) { + // TODO + } + + ROTATE0(Ray, i, pfAngles[i]); + ROTATE0(DetS, i, pfAngles[i]); + ROTATE0(DetU, i, pfAngles[i]); + + if (pfExtraOffsets) { + float d = pfExtraOffsets[i]; + p[i].fDetSX -= d * p[i].fDetUX; + p[i].fDetSY -= d * p[i].fDetUY; + } + } + +#undef ROTATE0 + + return p; +} + + +SFanProjection* genFanProjections(unsigned int iProjAngles, + unsigned int iProjDets, + double fOriginSource, double fOriginDetector, + double fDetSize, + const float *pfAngles) +// const float *pfExtraOffsets) +{ + SFanProjection *pProjs = new SFanProjection[iProjAngles]; + + float fSrcX0 = 0.0f; + float fSrcY0 = -fOriginSource; + float fDetUX0 = fDetSize; + float fDetUY0 = 0.0f; + float fDetSX0 = iProjDets * fDetUX0 / -2.0f; + float fDetSY0 = fOriginDetector; + +#define ROTATE0(name,i,alpha) do { pProjs[i].f##name##X = f##name##X0 * cos(alpha) - f##name##Y0 * sin(alpha); pProjs[i].f##name##Y = f##name##X0 * sin(alpha) + f##name##Y0 * cos(alpha); } while(0) + for (unsigned int i = 0; i < iProjAngles; ++i) { + ROTATE0(Src, i, pfAngles[i]); + ROTATE0(DetS, i, pfAngles[i]); + ROTATE0(DetU, i, pfAngles[i]); + } + +#undef ROTATE0 + + return pProjs; +} + +// Convert a SParProjection back into its set of "standard" circular parallel +// beam parameters. This is always possible. +bool getParParameters(const SParProjection &proj, unsigned int iProjDets, float &fAngle, float &fDetSize, float &fOffset) +{ + // Take part of DetU orthogonal to Ray + double ux = proj.fDetUX; + double uy = proj.fDetUY; + + double t = (ux * proj.fRayX + uy * proj.fRayY) / (proj.fRayX * proj.fRayX + proj.fRayY * proj.fRayY); + + ux -= t * proj.fRayX; + uy -= t * proj.fRayY; + + double angle = atan2(uy, ux); + + fAngle = (float)angle; + + double norm2 = uy * uy + ux * ux; + + fDetSize = (float)sqrt(norm2); + + // CHECKME: SIGNS? + fOffset = (float)(-0.5*iProjDets - (proj.fDetSY*uy + proj.fDetSX*ux) / norm2); + + return true; +} + +// Convert a SFanProjection back into its set of "standard" circular fan beam +// parameters. This will return false if it can not be represented in this way. +bool getFanParameters(const SFanProjection &proj, unsigned int iProjDets, float &fAngle, float &fOriginSource, float &fOriginDetector, float &fDetSize, float &fOffset) +{ + // angle + // det size + // offset + // origin-source + // origin-detector + + // Need to check if line source-origin is orthogonal to vector ux,uy + // (including the case source==origin) + + // (equivalent: source and origin project to same point on detector) + + double dp = proj.fSrcX * proj.fDetUX + proj.fSrcY * proj.fDetUY; + + double rel = (proj.fSrcX*proj.fSrcX + proj.fSrcY*proj.fSrcY) * (proj.fDetUX*proj.fDetUX + proj.fDetUY*proj.fDetUY); + rel = sqrt(rel); + + if (std::abs(dp) > rel * 0.0001) + return false; + + fOriginSource = sqrt(proj.fSrcX*proj.fSrcX + proj.fSrcY*proj.fSrcY); + + fDetSize = sqrt(proj.fDetUX*proj.fDetUX + proj.fDetUY*proj.fDetUY); + + // project origin on detector line ( == project source on detector line) + + double t = (- proj.fDetSX) * proj.fDetUX + (- proj.fDetSY) * proj.fDetUY; + + fOffset = (float)t - 0.5*iProjDets; + + // TODO: CHECKME + fOriginDetector = sqrt((proj.fDetSX + t * proj.fDetUX)*(proj.fDetSX + t * proj.fDetUX) + (proj.fDetSY + t * proj.fDetUY)*(proj.fDetSY + t * proj.fDetUY)); + + //float fAngle = atan2(proj.fDetSX + t * proj.fDetUX - proj.fSrcX, proj.fDetSY + t * proj.fDetUY); // TODO: Fix order + sign + fAngle = atan2(proj.fDetUY, proj.fDetUX); // TODO: Check order + sign + + return true; +} + + +} |