thresholding.h

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//
//
/*
    Copyright (C) 2000- 2007, Hammersmith Imanet Ltd
    This file is part of STIR.

    SPDX-License-Identifier: Apache-2.0

    See STIR/LICENSE.txt for details
*/
#ifndef __stir_thresholding_H__
#define __stir_thresholding_H__

#include "stir/min_positive_element.h"
#include <algorithm>

START_NAMESPACE_STIR


template <typename forw_iterT, typename elemT>
inline void
threshold_upper_lower(forw_iterT begin, forw_iterT end, const elemT new_min, const elemT new_max)
{
  for (forw_iterT iter = begin; iter != end; ++iter)
    {
      if (*iter > new_max)
        *iter = new_max;
      else if (new_min > *iter)
        *iter = new_min;
    }
}


template <typename forw_iterT, typename elemT>
inline void
threshold_upper(forw_iterT begin, forw_iterT end, const elemT new_max)
{
  for (forw_iterT iter = begin; iter != end; ++iter)
    {
      if (*iter > new_max)
        *iter = new_max;
    }
}


template <typename forw_iterT, typename elemT>
inline void
threshold_lower(forw_iterT begin, forw_iterT end, const elemT new_min)
{
  for (forw_iterT iter = begin; iter != end; ++iter)
    {
      if (new_min > *iter)
        *iter = new_min;
    }
}


template <typename ForwardIter_t, typename elemT>
void
threshold_min_to_small_positive_value(ForwardIter_t begin, ForwardIter_t end, const elemT& small_number)
{
  const ForwardIter_t smallest_positive_element_iter = min_positive_element(begin, end);

  if (smallest_positive_element_iter != end)
    threshold_lower(begin, end, (*smallest_positive_element_iter) * small_number);
  else
    std::fill(begin, end, small_number);
}


END_NAMESPACE_STIR

#endif