colmap · S-o-T · Aug 1, 2022
diff --git a/src/estimators/pose.cc b/src/estimators/pose.cc
@@ -200,7 +200,8 @@ bool RefineAbsolutePose(const AbsolutePoseRefinementOptions& options,
                         const std::vector<Eigen::Vector2d>& points2D,
                         const std::vector<Eigen::Vector3d>& points3D,
                         Eigen::Vector4d* qvec, Eigen::Vector3d* tvec,
-                        Camera* camera, Eigen::Matrix6d* rot_tvec_covariance) {
+                        Camera* camera, Eigen::Matrix6d* rot_tvec_covariance,
+                        ceres::Context* ceres_context) {
   CHECK_EQ(inlier_mask.size(), points2D.size());
   CHECK_EQ(points2D.size(), points3D.size());
   options.Check();
@@ -214,7 +215,9 @@ bool RefineAbsolutePose(const AbsolutePoseRefinementOptions& options,
 
   std::vector<Eigen::Vector3d> points3D_copy = points3D;
 
-  ceres::Problem problem;
+  ceres::Problem::Options problem_options;
+  problem_options.context = ceres_context;
+  ceres::Problem problem(problem_options);
 
   for (size_t i = 0; i < points2D.size(); ++i) {
     // Skip outlier observations
@@ -287,7 +290,7 @@ bool RefineAbsolutePose(const AbsolutePoseRefinementOptions& options,
   solver_options.linear_solver_type = ceres::DENSE_QR;
 
   // The overhead of creating threads is too large.
-  solver_options.num_threads = 1;
+  solver_options.num_threads = GetEffectiveNumThreads(options.num_threads);
 #if CERES_VERSION_MAJOR < 2
   solver_options.num_linear_solver_threads = 1;
 #endif  // CERES_VERSION_MAJOR

diff --git a/src/estimators/pose.h b/src/estimators/pose.h
@@ -97,6 +97,9 @@ struct AbsolutePoseRefinementOptions {
   // Whether to print final summary.
   bool print_summary = true;
 
+  // Number of threads to use during refinement.
+  int num_threads = 1;
+
   void Check() const {
     CHECK_GE(gradient_tolerance, 0.0);
     CHECK_GE(max_num_iterations, 0);
@@ -162,6 +165,7 @@ size_t EstimateRelativePose(const RANSACOptions& ransac_options,
 // @param rot_tvec_covariance  Estimated 6x6 covariance matrix of
 //                             the rotation (as axis-angle, in tangent space)
 //                             and translation terms (optional).
+// @param ceres_context        Ceres Solver internal context (optional).
 //
 // @return                     Whether the solution is usable.
 bool RefineAbsolutePose(const AbsolutePoseRefinementOptions& options,
@@ -170,7 +174,8 @@ bool RefineAbsolutePose(const AbsolutePoseRefinementOptions& options,
                         const std::vector<Eigen::Vector3d>& points3D,
                         Eigen::Vector4d* qvec, Eigen::Vector3d* tvec,
                         Camera* camera,
-                        Eigen::Matrix6d* rot_tvec_covariance = nullptr);
+                        Eigen::Matrix6d* rot_tvec_covariance = nullptr,
+                        ceres::Context* ceres_context = nullptr);
 
 // Refine relative pose of two cameras.
 //

diff --git a/src/optim/bundle_adjustment.cc b/src/optim/bundle_adjustment.cc
@@ -76,7 +76,10 @@ bool BundleAdjustmentOptions::Check() const {
 // BundleAdjustmentConfig
 ////////////////////////////////////////////////////////////////////////////////
 
-BundleAdjustmentConfig::BundleAdjustmentConfig() {}
+BundleAdjustmentConfig::BundleAdjustmentConfig() : ceres_context_(nullptr) {}
+
+BundleAdjustmentConfig::BundleAdjustmentConfig(ceres::Context* ceres_context)
+    : ceres_context_(ceres_context) {}
 
 size_t BundleAdjustmentConfig::NumImages() const { return image_ids_.size(); }
 
@@ -245,6 +248,10 @@ void BundleAdjustmentConfig::RemoveConstantPoint(const point3D_t point3D_id) {
   constant_point3D_ids_.erase(point3D_id);
 }
 
+ceres::Context* BundleAdjustmentConfig::GetCeresContext() const {
+  return ceres_context_;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // BundleAdjuster
 ////////////////////////////////////////////////////////////////////////////////
@@ -259,7 +266,9 @@ bool BundleAdjuster::Solve(Reconstruction* reconstruction) {
   CHECK_NOTNULL(reconstruction);
   CHECK(!problem_) << "Cannot use the same BundleAdjuster multiple times";
 
-  problem_.reset(new ceres::Problem());
+  ceres::Problem::Options problem_options;
+  problem_options.context = config_.GetCeresContext();
+  problem_.reset(new ceres::Problem(problem_options));
 
   ceres::LossFunction* loss_function = options_.CreateLossFunction();
   SetUp(reconstruction, loss_function);

diff --git a/src/optim/bundle_adjustment.h b/src/optim/bundle_adjustment.h
@@ -103,6 +103,7 @@ struct BundleAdjustmentOptions {
 class BundleAdjustmentConfig {
  public:
   BundleAdjustmentConfig();
+  explicit BundleAdjustmentConfig(ceres::Context *ceres_context);
 
   size_t NumImages() const;
   size_t NumPoints() const;
@@ -157,13 +158,15 @@ class BundleAdjustmentConfig {
   const std::unordered_set<point3D_t>& ConstantPoints() const;
   const std::vector<int>& ConstantTvec(const image_t image_id) const;
 
+  ceres::Context* GetCeresContext() const;
  private:
   std::unordered_set<camera_t> constant_camera_ids_;
   std::unordered_set<image_t> image_ids_;
   std::unordered_set<point3D_t> variable_point3D_ids_;
   std::unordered_set<point3D_t> constant_point3D_ids_;
   std::unordered_set<image_t> constant_poses_;
   std::unordered_map<image_t, std::vector<int>> constant_tvecs_;
+  ceres::Context* ceres_context_;
 };
 
 // Bundle adjustment based on Ceres-Solver. Enables most flexible configurations

diff --git a/src/sfm/incremental_mapper.cc b/src/sfm/incremental_mapper.cc
@@ -102,7 +102,8 @@ IncrementalMapper::IncrementalMapper(const DatabaseCache* database_cache)
       triangulator_(nullptr),
       num_total_reg_images_(0),
       num_shared_reg_images_(0),
-      prev_init_image_pair_id_(kInvalidImagePairId) {}
+      prev_init_image_pair_id_(kInvalidImagePairId),
+      ceres_context_(ceres::Context::Create()) {}
 
 void IncrementalMapper::BeginReconstruction(Reconstruction* reconstruction) {
   CHECK(reconstruction_ == nullptr);
@@ -450,6 +451,7 @@ bool IncrementalMapper::RegisterNextImage(const Options& options,
   abs_pose_options.ransac_options.confidence = 0.99999;
 
   AbsolutePoseRefinementOptions abs_pose_refinement_options;
+  abs_pose_refinement_options.num_threads = options.num_threads;
   if (num_reg_images_per_camera_[image.CameraId()] > 0) {
     // Camera already refined from another image with the same camera.
     if (camera.HasBogusParams(options.min_focal_length_ratio,
@@ -504,7 +506,8 @@ bool IncrementalMapper::RegisterNextImage(const Options& options,
 
   if (!RefineAbsolutePose(abs_pose_refinement_options, inlier_mask,
                           tri_points2D, tri_points3D, &image.Qvec(),
-                          &image.Tvec(), &camera)) {
+                          &image.Tvec(), &camera, nullptr,
+                          ceres_context_.get())) {
     return false;
   }
 
@@ -571,7 +574,7 @@ IncrementalMapper::AdjustLocalBundle(
 
   // Do the bundle adjustment only if there is any connected images.
   if (local_bundle.size() > 0) {
-    BundleAdjustmentConfig ba_config;
+    BundleAdjustmentConfig ba_config(ceres_context_.get());
     ba_config.AddImage(image_id);
     for (const image_t local_image_id : local_bundle) {
       ba_config.AddImage(local_image_id);
@@ -682,7 +685,7 @@ bool IncrementalMapper::AdjustGlobalBundle(
   reconstruction_->FilterObservationsWithNegativeDepth();
 
   // Configure bundle adjustment.
-  BundleAdjustmentConfig ba_config;
+  BundleAdjustmentConfig ba_config(ceres_context_.get());
   for (const image_t image_id : reg_image_ids) {
     ba_config.AddImage(image_id);
   }

diff --git a/src/sfm/incremental_mapper.h b/src/sfm/incremental_mapper.h
@@ -32,6 +32,8 @@
 #ifndef COLMAP_SRC_SFM_INCREMENTAL_MAPPER_H_
 #define COLMAP_SRC_SFM_INCREMENTAL_MAPPER_H_
 
+#include <ceres/context.h>
+
 #include "base/database.h"
 #include "base/database_cache.h"
 #include "base/reconstruction.h"
@@ -306,6 +308,8 @@ class IncrementalMapper {
   // This image list will be non-empty, if the reconstruction is continued from
   // an existing reconstruction.
   std::unordered_set<image_t> existing_image_ids_;
+
+  std::unique_ptr<ceres::Context> ceres_context_;
 };
 
 }  // namespace colmap