| // Copyright (c) 2022, ETH Zurich and UNC Chapel Hill. | |
| // All rights reserved. | |
| // | |
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| // | |
| // Author: Johannes L. Schoenberger (jsch-at-demuc-dot-de) | |
| namespace colmap { | |
| // Direct linear transformation algorithm to compute the homography between | |
| // point pairs. This algorithm computes the least squares estimate for | |
| // the homography from at least 4 correspondences. | |
| class HomographyMatrixEstimator { | |
| public: | |
| typedef Eigen::Vector2d X_t; | |
| typedef Eigen::Vector2d Y_t; | |
| typedef Eigen::Matrix3d M_t; | |
| // The minimum number of samples needed to estimate a model. | |
| static const int kMinNumSamples = 4; | |
| // Estimate the projective transformation (homography). | |
| // | |
| // The number of corresponding points must be at least 4. | |
| // | |
| // @param points1 First set of corresponding points. | |
| // @param points2 Second set of corresponding points. | |
| // | |
| // @return 3x3 homogeneous transformation matrix. | |
| static std::vector<M_t> Estimate(const std::vector<X_t>& points1, | |
| const std::vector<Y_t>& points2); | |
| // Calculate the transformation error for each corresponding point pair. | |
| // | |
| // Residuals are defined as the squared transformation error when | |
| // transforming the source to the destination coordinates. | |
| // | |
| // @param points1 First set of corresponding points. | |
| // @param points2 Second set of corresponding points. | |
| // @param H 3x3 projective matrix. | |
| // @param residuals Output vector of residuals. | |
| static void Residuals(const std::vector<X_t>& points1, | |
| const std::vector<Y_t>& points2, const M_t& H, | |
| std::vector<double>* residuals); | |
| }; | |
| } // namespace colmap | |