| // Copyright (c) 2022, ETH Zurich and UNC Chapel Hill. | |
| // All rights reserved. | |
| // | |
| // 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 ETH Zurich and UNC Chapel Hill 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 HOLDERS 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: Johannes L. Schoenberger (jsch-at-demuc-dot-de) | |
| namespace colmap { | |
| // Estimate a N-D translation transformation between point pairs. | |
| template <int kDim> | |
| class TranslationTransformEstimator { | |
| public: | |
| typedef Eigen::Matrix<double, kDim, 1> X_t; | |
| typedef Eigen::Matrix<double, kDim, 1> Y_t; | |
| typedef Eigen::Matrix<double, kDim, 1> M_t; | |
| // The minimum number of samples needed to estimate a model. | |
| static const int kMinNumSamples = 1; | |
| // Estimate the 2D translation transform. | |
| // | |
| // @param points1 Set of corresponding source 2D points. | |
| // @param points2 Set of corresponding destination 2D points. | |
| // | |
| // @return Translation vector. | |
| static std::vector<M_t> Estimate(const std::vector<X_t>& points1, | |
| const std::vector<Y_t>& points2); | |
| // Calculate the squared translation error. | |
| // | |
| // @param points1 Set of corresponding source 2D points. | |
| // @param points2 Set of corresponding destination 2D points. | |
| // @param translation Translation vector. | |
| // @param residuals Output vector of residuals for each point pair. | |
| static void Residuals(const std::vector<X_t>& points1, | |
| const std::vector<Y_t>& points2, const M_t& translation, | |
| std::vector<double>* residuals); | |
| }; | |
| //////////////////////////////////////////////////////////////////////////////// | |
| // Implementation | |
| //////////////////////////////////////////////////////////////////////////////// | |
| template <int kDim> | |
| std::vector<typename TranslationTransformEstimator<kDim>::M_t> | |
| TranslationTransformEstimator<kDim>::Estimate(const std::vector<X_t>& points1, | |
| const std::vector<Y_t>& points2) { | |
| CHECK_EQ(points1.size(), points2.size()); | |
| X_t mean_src = X_t::Zero(); | |
| Y_t mean_dst = Y_t::Zero(); | |
| for (size_t i = 0; i < points1.size(); ++i) { | |
| mean_src += points1[i]; | |
| mean_dst += points2[i]; | |
| } | |
| mean_src /= points1.size(); | |
| mean_dst /= points2.size(); | |
| std::vector<M_t> models(1); | |
| models[0] = mean_dst - mean_src; | |
| return models; | |
| } | |
| template <int kDim> | |
| void TranslationTransformEstimator<kDim>::Residuals( | |
| const std::vector<X_t>& points1, const std::vector<Y_t>& points2, | |
| const M_t& translation, std::vector<double>* residuals) { | |
| CHECK_EQ(points1.size(), points2.size()); | |
| residuals->resize(points1.size()); | |
| for (size_t i = 0; i < points1.size(); ++i) { | |
| const M_t diff = points2[i] - points1[i] - translation; | |
| (*residuals)[i] = diff.squaredNorm(); | |
| } | |
| } | |
| } // namespace colmap | |