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Diffstat (limited to 'include/astra/ParallelProjectionGeometry2D.h')
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diff --git a/include/astra/ParallelProjectionGeometry2D.h b/include/astra/ParallelProjectionGeometry2D.h new file mode 100644 index 0000000..c91fb4d --- /dev/null +++ b/include/astra/ParallelProjectionGeometry2D.h @@ -0,0 +1,153 @@ +/* +----------------------------------------------------------------------- +Copyright 2012 iMinds-Vision Lab, University of Antwerp + +Contact: astra@ua.ac.be +Website: http://astra.ua.ac.be + + +This file is part of the +All Scale Tomographic Reconstruction Antwerp Toolbox ("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/>. + +----------------------------------------------------------------------- +$Id$ +*/ + +#ifndef _INC_ASTRA_PARALLELPROJECTIONGEOMETRY2D +#define _INC_ASTRA_PARALLELPROJECTIONGEOMETRY2D + +#include "ProjectionGeometry2D.h" + +namespace astra +{ + +/** + * This class defines a 2D parallel beam projection geometry. + * + * <img src="../images/par_proj_geom.svg" width="600"/> + * This geometry is defined by a number of parameters: + * - The number of detectors (DetCount). + * The distance between the first detector and the projection of the origin \f$O\f$ is equal to + * the distance between the last detector and the projection of \f$O\f$. + * - The width of each detector (detector width). All detectors are equidistant. + * - A list of projection angles (\f$\theta\f$), measured w.r.t. the y-axis of the volume. In Radians. Should lie in the interval \f$[-\frac{\pi}{4},\frac{7\pi}{4}]\f$. + * + * This class provides functionality to convert between detector index and detector offset \f$t\f$. + * + * \par XML Configuration + * \astra_xml_item{DetectorCount, int, Number of detectors for each projection.} + * \astra_xml_item{DetectorWidth, float, Width of each detector.} + * \astra_xml_item{ProjectionAngles, vector of float, projection angles w.r.t. the y-axis of the volume in radians.} + * + * \par MATLAB example + * \astra_code{ + * proj_geom = astra_struct('parallel');\n + * proj_geom.DetectorCount = 512;\n + * proj_geom.DetectorWidth = 1.0;\n + * proj_geom.ProjectionAngles = linspace(0\,pi\,100);\n + * } + */ +class _AstraExport CParallelProjectionGeometry2D : public CProjectionGeometry2D +{ +public: + + /** Default constructor. Sets all numeric member variables to 0 and all pointer member variables to NULL. + * + * If an object is constructed using this default constructor, it must always be followed by a call + * to one of the init() methods before the object can be used. Any use before calling init() is not allowed, + * except calling the member function isInitialized(). + * + */ + CParallelProjectionGeometry2D(); + + /** Constructor. Create an instance of the CParallelProjectionGeometry2D class. + * + * @param _iProjectionAngleCount Number of projection angles. + * @param _iDetectorCount Number of detectors, i.e., the number of detector measurements for each projection angle. + * @param _fDetectorWidth Width of a detector cell, in unit lengths. All detector cells are assumed to have equal width. + * @param _pfProjectionAngles Pointer to an array of projection angles. The angles will be copied from this array. + */ + CParallelProjectionGeometry2D(int _iProjectionAngleCount, + int _iDetectorCount, + float32 _fDetectorWidth, + const float32* _pfProjectionAngles, + const float32* _pfExtraDetectorOffsets = 0); + + /** Copy constructor. + */ + CParallelProjectionGeometry2D(const CParallelProjectionGeometry2D& _projGeom); + + /** Destructor. + */ + ~CParallelProjectionGeometry2D(); + + /** Assignment operator. + */ + CParallelProjectionGeometry2D& operator=(const CParallelProjectionGeometry2D& _other); + + /** Initialize the geometry with a config object. + * + * @param _cfg Configuration Object + * @return initialization successful? + */ + virtual bool initialize(const Config& _cfg); + + /** Initialization. Initializes an instance of the CProjectionGeometry2D class. If the object has been + * initialized before, the object is reinitialized and memory is freed and reallocated if necessary. + * + * @param _iProjectionAngleCount Number of projection angles. + * @param _iDetectorCount Number of detectors, i.e., the number of detector measurements for each projection angle. + * @param _fDetectorWidth Width of a detector cell, in unit lengths. All detector cells are assumed to have equal width. + * @param _pfProjectionAngles Pointer to an array of projection angles. The angles will be copied from this array. + */ + bool initialize(int _iProjectionAngleCount, + int _iDetectorCount, + float32 _fDetectorWidth, + const float32* _pfProjectionAngles, + const float32* _pfExtraDetectorOffsets = 0); + + /** Create a hard copy. + */ + virtual CProjectionGeometry2D* clone(); + + /** Return true if this geometry instance is the same as the one specified. + * + * @return true if this geometry instance is the same as the one specified. + */ + virtual bool isEqual(CProjectionGeometry2D*) const; + + /** Returns true if the type of geometry defined in this class is the one specified in _sType. + * + * @param _sType geometry type to compare to. + * @return true if _sType == "parallel". + */ + virtual bool isOfType(const std::string& _sType); + + /** + * Returns a vector describing the direction of a ray belonging to a certain detector, + * the direction is the same for all detectors in one projection + * + * @param _iProjectionIndex index of projection + * @param _iProjectionIndex index of detector + * + * @return a unit vector describing the direction + */ + virtual CVector3D getProjectionDirection(int _iProjectionIndex, int _iDetectorIndex = 0); +}; + +} // namespace astra + +#endif /* _INC_ASTRA_PARALLELPROJECTIONGEOMETRY2D */ |