PriorWithParabolicSurrogate.h

Go to the documentation of this file.

//
//
/*
    Copyright (C) 2002- 2009, Hammersmith Imanet Ltd
    This file is part of STIR.

    SPDX-License-Identifier: Apache-2.0

    See STIR/LICENSE.txt for details
*/

#ifndef __stir_recon_buildblock_PriorWithParabolicSurrogate_H__
#define __stir_recon_buildblock_PriorWithParabolicSurrogate_H__

#include "stir/recon_buildblock/GeneralisedPrior.h"
#include "stir/BasicCoordinate.h"

START_NAMESPACE_STIR

template <typename TargetT>
class PriorWithParabolicSurrogate : public GeneralisedPrior<TargetT>
{
public:
  virtual void parabolic_surrogate_curvature(TargetT& parabolic_surrogate_curvature, const TargetT& current_estimate) = 0;


  virtual bool parabolic_surrogate_curvature_depends_on_argument() const { return true; }
#if 0
  // TODO this does not work for arbitrary TargetT, but only 3-dimensional things
  // maybe we could have a TargetT::index_type or so
  virtual void 
    compute_Hessian(TargetT& prior_Hessian_for_single_densel, 
                    const BasicCoordinate<3,int>& coords,
                    const TargetT &current_estimate) =0;
#endif
};

END_NAMESPACE_STIR

#endif