| // Ceres Solver - A fast non-linear least squares minimizer | 
 | // Copyright 2023 Google Inc. All rights reserved. | 
 | // http://ceres-solver.org/ | 
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 | // | 
 | // Author: keir@google.com (Keir Mierle) | 
 | // | 
 | // End-to-end bundle adjustment test utilities for Ceres. This base is used in | 
 | // the generated bundle adjustment test binaries. The reason to split the | 
 | // bundle tests into separate binaries is so the tests can get parallelized. | 
 |  | 
 | #include <cstdio> | 
 | #include <memory> | 
 | #include <string> | 
 |  | 
 | #include "absl/log/log.h" | 
 | #include "ceres/autodiff_cost_function.h" | 
 | #include "ceres/internal/export.h" | 
 | #include "ceres/ordered_groups.h" | 
 | #include "ceres/problem.h" | 
 | #include "ceres/rotation.h" | 
 | #include "ceres/solver.h" | 
 | #include "ceres/test_util.h" | 
 | #include "ceres/types.h" | 
 |  | 
 | namespace ceres { | 
 | namespace internal { | 
 |  | 
 | const bool kAutomaticOrdering = true; | 
 | const bool kUserOrdering = false; | 
 |  | 
 | // This class implements the SystemTestProblem interface and provides | 
 | // access to a bundle adjustment problem. It is based on | 
 | // examples/bundle_adjustment_example.cc. Currently a small 16 camera | 
 | // problem is hard coded in the constructor. | 
 | class BundleAdjustmentProblem { | 
 |  public: | 
 |   explicit BundleAdjustmentProblem(const std::string input_file) { | 
 |     ReadData(input_file); | 
 |     BuildProblem(); | 
 |   } | 
 |   BundleAdjustmentProblem() { | 
 |     const std::string input_file = | 
 |         TestFileAbsolutePath("problem-16-22106-pre.txt"); | 
 |     ReadData(input_file); | 
 |     BuildProblem(); | 
 |   } | 
 |  | 
 |   ~BundleAdjustmentProblem() { | 
 |     delete[] point_index_; | 
 |     delete[] camera_index_; | 
 |     delete[] observations_; | 
 |     delete[] parameters_; | 
 |   } | 
 |  | 
 |   Problem* mutable_problem() { return &problem_; } | 
 |   Solver::Options* mutable_solver_options() { return &options_; } | 
 |  | 
 |   // clang-format off | 
 |   int num_cameras()                const { return num_cameras_; } | 
 |   int num_points()                 const { return num_points_; } | 
 |   int num_observations()           const { return num_observations_; } | 
 |   const int* point_index()         const { return point_index_; } | 
 |   const int* camera_index()        const { return camera_index_; } | 
 |   const double* observations()     const { return observations_; } | 
 |   double* mutable_cameras()              { return parameters_; } | 
 |   double* mutable_points()               { return parameters_ + 9 * num_cameras_; } | 
 |   const Solver::Options& options() const { return options_; } | 
 |   // clang-format on | 
 |  | 
 |   static constexpr double kResidualTolerance = 1e-4; | 
 |  | 
 |  private: | 
 |   void ReadData(const std::string& filename) { | 
 |     FILE* fptr = fopen(filename.c_str(), "r"); | 
 |  | 
 |     if (!fptr) { | 
 |       LOG(FATAL) << "File Error: unable to open file " << filename; | 
 |     } | 
 |  | 
 |     // This will die horribly on invalid files. Them's the breaks. | 
 |     FscanfOrDie(fptr, "%d", &num_cameras_); | 
 |     FscanfOrDie(fptr, "%d", &num_points_); | 
 |     FscanfOrDie(fptr, "%d", &num_observations_); | 
 |  | 
 |     VLOG(1) << "Header: " << num_cameras_ << " " << num_points_ << " " | 
 |             << num_observations_; | 
 |  | 
 |     point_index_ = new int[num_observations_]; | 
 |     camera_index_ = new int[num_observations_]; | 
 |     observations_ = new double[2 * num_observations_]; | 
 |  | 
 |     num_parameters_ = 9 * num_cameras_ + 3 * num_points_; | 
 |     parameters_ = new double[num_parameters_]; | 
 |  | 
 |     for (int i = 0; i < num_observations_; ++i) { | 
 |       FscanfOrDie(fptr, "%d", camera_index_ + i); | 
 |       FscanfOrDie(fptr, "%d", point_index_ + i); | 
 |       for (int j = 0; j < 2; ++j) { | 
 |         FscanfOrDie(fptr, "%lf", observations_ + 2 * i + j); | 
 |       } | 
 |     } | 
 |  | 
 |     for (int i = 0; i < num_parameters_; ++i) { | 
 |       FscanfOrDie(fptr, "%lf", parameters_ + i); | 
 |     } | 
 |  | 
 |     fclose(fptr); | 
 |   } | 
 |  | 
 |   void BuildProblem() { | 
 |     double* points = mutable_points(); | 
 |     double* cameras = mutable_cameras(); | 
 |  | 
 |     for (int i = 0; i < num_observations(); ++i) { | 
 |       // Each Residual block takes a point and a camera as input and | 
 |       // outputs a 2 dimensional residual. | 
 |       CostFunction* cost_function = | 
 |           new AutoDiffCostFunction<BundlerResidual, 2, 9, 3>( | 
 |               new BundlerResidual(observations_[2 * i + 0], | 
 |                                   observations_[2 * i + 1])); | 
 |  | 
 |       // Each observation corresponds to a pair of a camera and a point | 
 |       // which are identified by camera_index()[i] and | 
 |       // point_index()[i] respectively. | 
 |       double* camera = cameras + 9 * camera_index_[i]; | 
 |       double* point = points + 3 * point_index()[i]; | 
 |       problem_.AddResidualBlock(cost_function, nullptr, camera, point); | 
 |     } | 
 |  | 
 |     options_.linear_solver_ordering = | 
 |         std::make_shared<ParameterBlockOrdering>(); | 
 |  | 
 |     // The points come before the cameras. | 
 |     for (int i = 0; i < num_points_; ++i) { | 
 |       options_.linear_solver_ordering->AddElementToGroup(points + 3 * i, 0); | 
 |     } | 
 |  | 
 |     for (int i = 0; i < num_cameras_; ++i) { | 
 |       options_.linear_solver_ordering->AddElementToGroup(cameras + 9 * i, 1); | 
 |     } | 
 |  | 
 |     options_.linear_solver_type = DENSE_SCHUR; | 
 |     options_.max_num_iterations = 25; | 
 |     options_.function_tolerance = 1e-10; | 
 |     options_.gradient_tolerance = 1e-10; | 
 |     options_.parameter_tolerance = 1e-10; | 
 |   } | 
 |  | 
 |   template <typename T> | 
 |   void FscanfOrDie(FILE* fptr, const char* format, T* value) { | 
 |     int num_scanned = fscanf(fptr, format, value); | 
 |     if (num_scanned != 1) { | 
 |       LOG(FATAL) << "Invalid UW data file."; | 
 |     } | 
 |   } | 
 |  | 
 |   // Templated pinhole camera model.  The camera is parameterized | 
 |   // using 9 parameters. 3 for rotation, 3 for translation, 1 for | 
 |   // focal length and 2 for radial distortion. The principal point is | 
 |   // not modeled (i.e. it is assumed to be located at the image | 
 |   // center). | 
 |   struct BundlerResidual { | 
 |     // (u, v): the position of the observation with respect to the image | 
 |     // center point. | 
 |     BundlerResidual(double u, double v) : u(u), v(v) {} | 
 |  | 
 |     template <typename T> | 
 |     bool operator()(const T* const camera, | 
 |                     const T* const point, | 
 |                     T* residuals) const { | 
 |       T p[3]; | 
 |       AngleAxisRotatePoint(camera, point, p); | 
 |  | 
 |       // Add the translation vector | 
 |       p[0] += camera[3]; | 
 |       p[1] += camera[4]; | 
 |       p[2] += camera[5]; | 
 |  | 
 |       const T& focal = camera[6]; | 
 |       const T& l1 = camera[7]; | 
 |       const T& l2 = camera[8]; | 
 |  | 
 |       // Compute the center of distortion.  The sign change comes from | 
 |       // the camera model that Noah Snavely's Bundler assumes, whereby | 
 |       // the camera coordinate system has a negative z axis. | 
 |       T xp = -focal * p[0] / p[2]; | 
 |       T yp = -focal * p[1] / p[2]; | 
 |  | 
 |       // Apply second and fourth order radial distortion. | 
 |       T r2 = xp * xp + yp * yp; | 
 |       T distortion = T(1.0) + r2 * (l1 + l2 * r2); | 
 |  | 
 |       residuals[0] = distortion * xp - u; | 
 |       residuals[1] = distortion * yp - v; | 
 |  | 
 |       return true; | 
 |     } | 
 |  | 
 |     double u; | 
 |     double v; | 
 |   }; | 
 |  | 
 |   Problem problem_; | 
 |   Solver::Options options_; | 
 |  | 
 |   int num_cameras_; | 
 |   int num_points_; | 
 |   int num_observations_; | 
 |   int num_parameters_; | 
 |  | 
 |   int* point_index_; | 
 |   int* camera_index_; | 
 |   double* observations_; | 
 |   // The parameter vector is laid out as follows | 
 |   // [camera_1, ..., camera_n, point_1, ..., point_m] | 
 |   double* parameters_; | 
 | }; | 
 |  | 
 | using BundleAdjustmentTest = SystemTest<BundleAdjustmentProblem>; | 
 |  | 
 | }  // namespace internal | 
 | }  // namespace ceres |