/*========================================================================= * * Copyright NumFOCUS * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0.txt * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * *=========================================================================*/ #ifndef itkVersorRigid3DTransformOptimizer_h #define itkVersorRigid3DTransformOptimizer_h #include "itkRegularStepGradientDescentOptimizer.h" #include "itkVersor.h" #include "ITKOptimizersExport.h" namespace itk { /** \class VersorRigid3DTransformOptimizer * \brief Implement a gradient descent optimizer for the VersorRigid3DTransform * parameter space. * * VersorRigid3DTransformOptimizer is a variant of the gradient descent * optimizer implemented in RegularStepGradientDescentOptimizer. * * Versors are not in a vector space, for that reason, the classical gradient * descent algorithm has to be modified in order to be applicable to Versors * (unit quaternions) that form the group SO(3). * * The Versor space has only three degrees of freedom, even though Versors are * represented using four values. * * This optimizer assumes that the CostFunction to be optimized has an * itk::Versor and an itk::Vector as parameters. * * \sa RegularStepGradientDescentOptimizer * \sa Versor * \sa VersorRigid3DTransform * * \ingroup Numerics Optimizers * \ingroup ITKOptimizers */ class ITKOptimizers_EXPORT VersorRigid3DTransformOptimizer : public RegularStepGradientDescentBaseOptimizer { public: ITK_DISALLOW_COPY_AND_MOVE(VersorRigid3DTransformOptimizer); /** Standard class type aliases. */ using Self = VersorRigid3DTransformOptimizer; using Superclass = RegularStepGradientDescentBaseOptimizer; using Pointer = SmartPointer; using ConstPointer = SmartPointer; /** Method for creation through the object factory. */ itkNewMacro(Self); /** Run-time type information (and related methods). */ itkTypeMacro(VersorRigid3DTransformOptimizer, RegularStepGradientDescentBaseOptimizer); /** This class is specialized for 3D */ static constexpr unsigned int SpaceDimension = 6; /** Versor Type */ using VersorType = Versor; using VectorType = VersorType::VectorType; /** Advance one step following the gradient direction. */ void StepAlongGradient(double factor, const DerivativeType & transformedGradient) override; protected: VersorRigid3DTransformOptimizer() = default; ~VersorRigid3DTransformOptimizer() override = default; }; } // end namespace itk #endif