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/*
-----------------------------------------------------------------------
Copyright: 2010-2018, imec Vision Lab, University of Antwerp
2014-2018, CWI, Amsterdam
Contact: astra@astra-toolbox.com
Website: http://www.astra-toolbox.com/
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/>.
-----------------------------------------------------------------------
*/
#include "algo.h"
#include "astra/Filters.h"
namespace astraCUDA {
class _AstraExport FBP : public ReconAlgo {
public:
FBP();
~FBP();
virtual bool useSinogramMask() { return false; }
virtual bool useVolumeMask() { return false; }
// Returns the required size of a filter in the fourier domain
// when multiplying it with the fft of the projection data.
// Its value is equal to the smallest power of two larger than
// or equal to twice the number of detectors in the spatial domain.
//
// _iDetectorCount is the number of detectors in the spatial domain.
static int calcFourierFilterSize(int _iDetectorCount);
// Sets the filter type. Some filter types require the user to supply an
// array containing the filter.
// The number of elements in a filter in the fourier domain should be equal
// to the value returned by calcFourierFilterSize().
// The following types require a filter:
//
// - FILTER_PROJECTION:
// The filter size should be equal to the output of
// calcFourierFilterSize(). The filtered sinogram is
// multiplied with the supplied filter.
//
// - FILTER_SINOGRAM:
// Same as FILTER_PROJECTION, but now the filter should contain a row for
// every projection direction.
//
// - FILTER_RPROJECTION:
// The filter should now contain one kernel (= ifft of filter), with the
// peak in the center. The filter width
// can be any value. If odd, the peak is assumed to be in the center, if
// even, it is assumed to be at floor(filter-width/2).
//
// - FILTER_RSINOGRAM
// Same as FILTER_RPROJECTION, but now the supplied filter should contain a
// row for every projection direction.
//
// A large number of other filters (FILTER_RAMLAK, FILTER_SHEPPLOGAN,
// FILTER_COSINE, FILTER_HAMMING, and FILTER_HANN)
// have a D variable, which gives the cutoff point in the frequency domain.
// Setting this value to 1.0 will include the whole filter
bool setFilter(const astra::SFilterConfig &_cfg);
bool setShortScan(bool ss) { m_bShortScan = ss; return true; }
// Scale the final reconstruction.
// May be called at any time before iterate().
bool setReconstructionScale(float fScale);
virtual bool init();
virtual bool iterate(unsigned int iterations);
virtual float computeDiffNorm() { return 0.0f; } // TODO
protected:
void reset();
void* D_filter; // cufftComplex*
bool m_bShortScan;
float fReconstructionScale;
};
}
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