Line data    Source code

       1             : #pragma once
       2             : 
       3             : #include "Functional.h"
       4             : 
       5             : namespace elsa
       6             : {
       7             :     /**
       8             :      * @brief Class representing the Pseudohuber norm.
       9             :      *
      10             :      * @author Matthias Wieczorek - initial code
      11             :      * @author Maximilian Hornung - modularization
      12             :      * @author Tobias Lasser - modernization, fixes
      13             :      *
      14             :      * @tparam data_t data type for the domain of the residual of the functional, defaulting to
      15             :      * real_t
      16             :      *
      17             :      * The Pseudohuber norm evaluates to \f$ \sum_{i=1}^n \delta \left( \sqrt{1 + (x_i / \delta)^2}
      18             :      * - 1 \right) \f$ for \f$ x=(x_i)_{i=1}^n \f$ and a slope parameter \f$ \delta \f$.
      19             :      *
      20             :      * Reference: https://doi.org/10.1109%2F83.551699
      21             :      */
      22             :     template <typename data_t = real_t>
      23             :     class PseudoHuber : public Functional<data_t>
      24             :     {
      25             :     public:
      26             :         /**
      27             :          * @brief Constructor for the Pseudohuber functional, mapping domain vector to scalar
      28             :          * (without a residual)
      29             :          *
      30             :          * @param[in] domainDescriptor describing the domain of the functional
      31             :          * @param[in] delta parameter for linear slope (defaults to 1)
      32             :          */
      33             :         explicit PseudoHuber(const DataDescriptor& domainDescriptor,
      34             :                              real_t delta = static_cast<real_t>(1));
      35             : 
      36             :         /**
      37             :          * @brief Constructor for the Pseudohuber functional, using a residual as input to map to a
      38             :          * scalar
      39             :          *
      40             :          * @param[in] residual to be used when evaluating the functional (or its derivative)
      41             :          * @param[in] delta parameter for linear slope (defaults to 1)
      42             :          */
      43             :         explicit PseudoHuber(const Residual<data_t>& residual,
      44             :                              real_t delta = static_cast<real_t>(1));
      45             : 
      46             :         /// make copy constructor deletion explicit
      47             :         PseudoHuber(const PseudoHuber<data_t>&) = delete;
      48             : 
      49             :         /// default destructor
      50          16 :         ~PseudoHuber() override = default;
      51             : 
      52             :     protected:
      53             :         /// the evaluation of the Huber norm
      54             :         data_t evaluateImpl(const DataContainer<data_t>& Rx) override;
      55             : 
      56             :         /// the computation of the gradient (in place)
      57             :         void getGradientInPlaceImpl(DataContainer<data_t>& Rx) override;
      58             : 
      59             :         /// the computation of the Hessian
      60             :         LinearOperator<data_t> getHessianImpl(const DataContainer<data_t>& Rx) override;
      61             : 
      62             :         /// implement the polymorphic clone operation
      63             :         PseudoHuber<data_t>* cloneImpl() const override;
      64             : 
      65             :         /// implement the polymorphic comparison operation
      66             :         bool isEqual(const Functional<data_t>& other) const override;
      67             : 
      68             :     private:
      69             :         /// the slope delta
      70             :         const real_t _delta;
      71             :     };
      72             : 
      73             : } // namespace elsa