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Diffstat (limited to 'extern/ceres/include/ceres/sphere_manifold.h')
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diff --git a/extern/ceres/include/ceres/sphere_manifold.h b/extern/ceres/include/ceres/sphere_manifold.h new file mode 100644 index 00000000000..5d71cbbca9a --- /dev/null +++ b/extern/ceres/include/ceres/sphere_manifold.h @@ -0,0 +1,231 @@ +// Ceres Solver - A fast non-linear least squares minimizer +// Copyright 2022 Google Inc. All rights reserved. +// http://ceres-solver.org/ +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are met: +// +// * Redistributions of source code must retain the above copyright notice, +// this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above copyright notice, +// this list of conditions and the following disclaimer in the documentation +// and/or other materials provided with the distribution. +// * Neither the name of Google Inc. nor the names of its contributors may be +// used to endorse or promote products derived from this software without +// specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +// POSSIBILITY OF SUCH DAMAGE. +// +// Author: vitus@google.com (Mike Vitus) +// jodebo_beck@gmx.de (Johannes Beck) + +#ifndef CERES_PUBLIC_SPHERE_MANIFOLD_H_ +#define CERES_PUBLIC_SPHERE_MANIFOLD_H_ + +#include <Eigen/Core> +#include <algorithm> +#include <array> +#include <memory> +#include <vector> + +#include "ceres/internal/disable_warnings.h" +#include "ceres/internal/export.h" +#include "ceres/internal/householder_vector.h" +#include "ceres/internal/sphere_manifold_functions.h" +#include "ceres/manifold.h" +#include "ceres/types.h" +#include "glog/logging.h" + +namespace ceres { + +// This provides a manifold on a sphere meaning that the norm of the vector +// stays the same. Such cases often arises in Structure for Motion +// problems. One example where they are used is in representing points whose +// triangulation is ill-conditioned. Here it is advantageous to use an +// over-parameterization since homogeneous vectors can represent points at +// infinity. +// +// The plus operator is defined as +// Plus(x, delta) = +// [sin(0.5 * |delta|) * delta / |delta|, cos(0.5 * |delta|)] * x +// +// The minus operator is defined as +// Minus(x, y) = 2 atan2(nhy, y[-1]) / nhy * hy[0 : size_ - 1] +// with nhy = norm(hy[0 : size_ - 1]) +// +// with * defined as an operator which applies the update orthogonal to x to +// remain on the sphere. The ambient space dimension is required to be greater +// than 1. +// +// The class works with dynamic and static ambient space dimensions. If the +// ambient space dimensions is known at compile time use +// +// SphereManifold<3> manifold; +// +// If the ambient space dimensions is not known at compile time the template +// parameter needs to be set to ceres::DYNAMIC and the actual dimension needs +// to be provided as a constructor argument: +// +// SphereManifold<ceres::DYNAMIC> manifold(ambient_dim); +// +// See section B.2 (p.25) in "Integrating Generic Sensor Fusion Algorithms +// with Sound State Representations through Encapsulation of Manifolds" by C. +// Hertzberg, R. Wagner, U. Frese and L. Schroder for more details +// (https://arxiv.org/pdf/1107.1119.pdf) +template <int AmbientSpaceDimension> +class SphereManifold final : public Manifold { + public: + static_assert( + AmbientSpaceDimension == ceres::DYNAMIC || AmbientSpaceDimension > 1, + "The size of the homogeneous vector needs to be greater than 1."); + static_assert(ceres::DYNAMIC == Eigen::Dynamic, + "ceres::DYNAMIC needs to be the same as Eigen::Dynamic."); + + SphereManifold(); + explicit SphereManifold(int size); + + int AmbientSize() const override { + return AmbientSpaceDimension == ceres::DYNAMIC ? size_ + : AmbientSpaceDimension; + } + int TangentSize() const override { return AmbientSize() - 1; } + + bool Plus(const double* x, + const double* delta, + double* x_plus_delta) const override; + bool PlusJacobian(const double* x, double* jacobian) const override; + + bool Minus(const double* y, + const double* x, + double* y_minus_x) const override; + bool MinusJacobian(const double* x, double* jacobian) const override; + + private: + static constexpr int TangentSpaceDimension = + AmbientSpaceDimension > 0 ? AmbientSpaceDimension - 1 : Eigen::Dynamic; + + using AmbientVector = Eigen::Matrix<double, AmbientSpaceDimension, 1>; + using TangentVector = Eigen::Matrix<double, TangentSpaceDimension, 1>; + using MatrixPlusJacobian = Eigen::Matrix<double, + AmbientSpaceDimension, + TangentSpaceDimension, + Eigen::RowMajor>; + using MatrixMinusJacobian = Eigen::Matrix<double, + TangentSpaceDimension, + AmbientSpaceDimension, + Eigen::RowMajor>; + + const int size_{}; +}; + +template <int AmbientSpaceDimension> +SphereManifold<AmbientSpaceDimension>::SphereManifold() + : size_{AmbientSpaceDimension} { + static_assert( + AmbientSpaceDimension != Eigen::Dynamic, + "The size is set to dynamic. Please call the constructor with a size."); +} + +template <int AmbientSpaceDimension> +SphereManifold<AmbientSpaceDimension>::SphereManifold(int size) : size_{size} { + if (AmbientSpaceDimension != Eigen::Dynamic) { + CHECK_EQ(AmbientSpaceDimension, size) + << "Specified size by template parameter differs from the supplied " + "one."; + } else { + CHECK_GT(size_, 1) + << "The size of the manifold needs to be greater than 1."; + } +} + +template <int AmbientSpaceDimension> +bool SphereManifold<AmbientSpaceDimension>::Plus( + const double* x_ptr, + const double* delta_ptr, + double* x_plus_delta_ptr) const { + Eigen::Map<const AmbientVector> x(x_ptr, size_); + Eigen::Map<const TangentVector> delta(delta_ptr, size_ - 1); + Eigen::Map<AmbientVector> x_plus_delta(x_plus_delta_ptr, size_); + + const double norm_delta = delta.norm(); + + if (norm_delta == 0.0) { + x_plus_delta = x; + return true; + } + + AmbientVector v(size_); + double beta; + + // NOTE: The explicit template arguments are needed here because + // ComputeHouseholderVector is templated and some versions of MSVC + // have trouble deducing the type of v automatically. + internal::ComputeHouseholderVector<Eigen::Map<const AmbientVector>, + double, + AmbientSpaceDimension>(x, &v, &beta); + + internal::ComputeSphereManifoldPlus( + v, beta, x, delta, norm_delta, &x_plus_delta); + + return true; +} + +template <int AmbientSpaceDimension> +bool SphereManifold<AmbientSpaceDimension>::PlusJacobian( + const double* x_ptr, double* jacobian_ptr) const { + Eigen::Map<const AmbientVector> x(x_ptr, size_); + Eigen::Map<MatrixPlusJacobian> jacobian(jacobian_ptr, size_, size_ - 1); + internal::ComputeSphereManifoldPlusJacobian(x, &jacobian); + + return true; +} + +template <int AmbientSpaceDimension> +bool SphereManifold<AmbientSpaceDimension>::Minus(const double* y_ptr, + const double* x_ptr, + double* y_minus_x_ptr) const { + AmbientVector y = Eigen::Map<const AmbientVector>(y_ptr, size_); + Eigen::Map<const AmbientVector> x(x_ptr, size_); + Eigen::Map<TangentVector> y_minus_x(y_minus_x_ptr, size_ - 1); + + // Apply hoseholder transformation. + AmbientVector v(size_); + double beta; + + // NOTE: The explicit template arguments are needed here because + // ComputeHouseholderVector is templated and some versions of MSVC + // have trouble deducing the type of v automatically. + internal::ComputeHouseholderVector<Eigen::Map<const AmbientVector>, + double, + AmbientSpaceDimension>(x, &v, &beta); + internal::ComputeSphereManifoldMinus(v, beta, x, y, &y_minus_x); + return true; +} + +template <int AmbientSpaceDimension> +bool SphereManifold<AmbientSpaceDimension>::MinusJacobian( + const double* x_ptr, double* jacobian_ptr) const { + Eigen::Map<const AmbientVector> x(x_ptr, size_); + Eigen::Map<MatrixMinusJacobian> jacobian(jacobian_ptr, size_ - 1, size_); + + internal::ComputeSphereManifoldMinusJacobian(x, &jacobian); + return true; +} + +} // namespace ceres + +// clang-format off +#include "ceres/internal/reenable_warnings.h" +// clang-format on + +#endif // CERES_PUBLIC_SPHERE_MANIFOLD_H_ |