Line data    Source code

       1             : #pragma once
       2             : 
       3             : #include "ProximityOperator.h"
       4             : 
       5             : namespace elsa
       6             : {
       7             :     /**
       8             :      * @brief Class representing the proximity operator of the l0 pseudo-norm
       9             :      *
      10             :      * @author Andi Braimllari - initial code
      11             :      *
      12             :      * @tparam data_t data type for the values of the operator, defaulting to real_t
      13             :      *
      14             :      * This class represents the hard thresholding operator, expressed by its apply method through
      15             :      * the function i.e. @f$ prox(v) = v·1_{\{|v| > t\}}. @f$
      16             :      *
      17             :      * References:
      18             :      * http://sfb649.wiwi.hu-berlin.de/fedc_homepage/xplore/tutorials/xlghtmlnode93.html
      19             :      */
      20             :     template <typename data_t = real_t>
      21             :     class HardThresholding : public ProximityOperator<data_t>
      22             :     {
      23             :     public:
      24             :         /**
      25             :          * @brief Construct a HardThresholding operator from the given DataDescriptor
      26             :          *
      27             :          * @param[in] descriptor DataDescriptor describing the operator values
      28             :          */
      29             :         HardThresholding(const DataDescriptor& descriptor);
      30             : 
      31             :         /// default destructor
      32          40 :         ~HardThresholding() override = default;
      33             : 
      34             :     protected:
      35             :         /**
      36             :          * @brief apply the proximity operator of the l0 pseudo-norm to an element in the operator's
      37             :          * domain
      38             :          *
      39             :          * @param[in] v input DataContainer
      40             :          * @param[in] t input Threshold
      41             :          * @param[out] prox output DataContainer
      42             :          */
      43             :         void applyImpl(const DataContainer<data_t>& v, geometry::Threshold<data_t> t,
      44             :                        DataContainer<data_t>& prox) const override;
      45             : 
      46             :         /// implement the polymorphic clone operation
      47             :         auto cloneImpl() const -> HardThresholding<data_t>* override;
      48             : 
      49             :         /// implement the polymorphic comparison operation
      50             :         auto isEqual(const ProximityOperator<data_t>& other) const -> bool override;
      51             :     };
      52             : } // namespace elsa