1 /*========================================================================= 2 * 3 * Copyright Insight Software Consortium 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0.txt 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 *=========================================================================*/ 18 #ifndef itkHeavisideStepFunction_h 19 #define itkHeavisideStepFunction_h 20 21 #include "itkHeavisideStepFunctionBase.h" 22 #include "itkNumericTraits.h" 23 24 namespace itk 25 { 26 /** \class HeavisideStepFunction 27 * 28 * \brief Implementation of the classical Heaviside step function. 29 * 30 * The Heaviside Step function is a piece-wise function: 31 * 32 * http://en.wikipedia.org/wiki/Heaviside_step_function 33 * 34 * 35 * \author Mosaliganti K., Smith B., Gelas A., Gouaillard A., Megason S. 36 * 37 * This code was taken from the Insight Journal paper: 38 * 39 * "Cell Tracking using Coupled Active Surfaces for Nuclei and Membranes" 40 * http://www.insight-journal.org/browse/publication/642 41 * https://hdl.handle.net/10380/3055 42 * 43 * That is based on the papers: 44 * 45 * "Level Set Segmentation: Active Contours without edge" 46 * http://www.insight-journal.org/browse/publication/322 47 * https://hdl.handle.net/1926/1532 48 * 49 * and 50 * 51 * "Level set segmentation using coupled active surfaces" 52 * http://www.insight-journal.org/browse/publication/323 53 * https://hdl.handle.net/1926/1533 54 * 55 * 56 * \ingroup ITKCommon 57 */ 58 template< typename TInput = float, typename TOutput = double > 59 class ITK_TEMPLATE_EXPORT HeavisideStepFunction: 60 public HeavisideStepFunctionBase< TInput, TOutput > 61 { 62 public: 63 ITK_DISALLOW_COPY_AND_ASSIGN(HeavisideStepFunction); 64 65 using Self = HeavisideStepFunction; 66 using Superclass = HeavisideStepFunctionBase< TInput, TOutput >; 67 using Pointer = SmartPointer< Self >; 68 using ConstPointer = SmartPointer< const Self >; 69 70 itkNewMacro(Self); 71 72 itkTypeMacro(HeavisideStepFunction, HeavisideStepFunctionBase); 73 74 using InputType = typename Superclass::InputType; 75 using OutputType = typename Superclass::OutputType; 76 77 /** Evaluate at the specified input position */ 78 OutputType Evaluate(const InputType & input) const override; 79 80 /** Evaluate the derivative at the specified input position */ 81 OutputType EvaluateDerivative(const InputType & input) const override; 82 83 protected: 84 HeavisideStepFunction(); 85 ~HeavisideStepFunction() override = default; 86 }; 87 } 88 89 #ifndef ITK_MANUAL_INSTANTIATION 90 #include "itkHeavisideStepFunction.hxx" 91 #endif 92 93 #endif 94