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Merged
ahojnnes merged 5 commits into from
Nov 22, 2025
Merged

View graph simplification #225

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6271afb
Update to latest colmap and use L1 solver + union-find from colmap
ahojnnes Nov 20, 2025
4b8a229
Simplify view graph
ahojnnes Nov 21, 2025
c3c6269
Merge branch 'main' of https://github.com/colmap/glomap into user/jsc…
ahojnnes Nov 22, 2025
fac6a3f
d
ahojnnes Nov 22, 2025
f4a0c72
d
ahojnnes Nov 22, 2025
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2 changes: 1 addition & 1 deletion glomap/estimators/global_rotation_averaging.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -121,7 +121,7 @@ void RotationEstimator::InitializeFromMaximumSpanningTree(

// Directly use the relative pose for estimation rotation
const ImagePair& image_pair = view_graph.image_pairs.at(
ImagePair::ImagePairToPairId(curr, parents[curr]));
colmap::ImagePairToPairId(curr, parents[curr]));
if (image_pair.image_id1 == curr) {
// 1_R_w = 2_R_1^T * 2_R_w
cam_from_worlds[curr].rotation =
Expand Down
35 changes: 16 additions & 19 deletions glomap/estimators/gravity_refinement.cc
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Expand Up @@ -9,12 +9,10 @@ namespace glomap {
void GravityRefiner::RefineGravity(const ViewGraph& view_graph,
std::unordered_map<frame_t, Frame>& frames,
std::unordered_map<image_t, Image>& images) {
const std::unordered_map<image_pair_t, ImagePair>& image_pairs =
view_graph.image_pairs;
const std::unordered_map<image_t, std::unordered_set<image_t>>&
adjacency_list = view_graph.GetAdjacencyList();
adjacency_list = view_graph.CreateImageAdjacencyList();
if (adjacency_list.empty()) {
LOG(INFO) << "Adjacency list not established" << std::endl;
LOG(INFO) << "Adjacency list not established";
return;
}

Expand All @@ -24,16 +22,16 @@ void GravityRefiner::RefineGravity(const ViewGraph& view_graph,
IdentifyErrorProneGravity(view_graph, frames, images, error_prone_frames);

if (error_prone_frames.empty()) {
LOG(INFO) << "No error prone frames found" << std::endl;
LOG(INFO) << "No error prone frames found";
return;
}
// Get the relevant pair ids for frames
std::unordered_map<frame_t, std::unordered_set<image_pair_t>>
adjacency_list_frames_to_pair_id;
for (auto& [image_id, neighbors] : adjacency_list) {
for (auto neighbor : neighbors) {
for (const auto& neighbor : neighbors) {
adjacency_list_frames_to_pair_id[images[image_id].frame_id].insert(
ImagePair::ImagePairToPairId(image_id, neighbor));
colmap::ImagePairToPairId(image_id, neighbor));
}
}

Expand All @@ -59,8 +57,8 @@ void GravityRefiner::RefineGravity(const ViewGraph& view_graph,
int counter = 0;
Eigen::Vector3d gravity = frames[frame_id].gravity_info.GetGravity();
for (const auto& pair_id : neighbors) {
image_t image_id1 = image_pairs.at(pair_id).image_id1;
image_t image_id2 = image_pairs.at(pair_id).image_id2;
const image_t image_id1 = view_graph.image_pairs.at(pair_id).image_id1;
const image_t image_id2 = view_graph.image_pairs.at(pair_id).image_id2;
if (!images.at(image_id1).HasGravity() ||
!images.at(image_id2).HasGravity())
continue;
Expand All @@ -82,17 +80,18 @@ void GravityRefiner::RefineGravity(const ViewGraph& view_graph,
// consider a single cost term
if (images.at(image_id1).frame_id == frame_id) {
gravities.emplace_back(
(colmap::Inverse(image_pairs.at(pair_id).cam2_from_cam1 *
(colmap::Inverse(view_graph.image_pairs.at(pair_id).cam2_from_cam1 *
cam1_from_rig1)
.rotation.toRotationMatrix() *
images[image_id2].GetRAlign())
.col(1));
} else if (images.at(image_id2).frame_id == frame_id) {
gravities.emplace_back(((colmap::Inverse(cam2_from_rig2) *
image_pairs.at(pair_id).cam2_from_cam1)
.rotation.toRotationMatrix() *
images[image_id1].GetRAlign())
.col(1));
gravities.emplace_back(
((colmap::Inverse(cam2_from_rig2) *
view_graph.image_pairs.at(pair_id).cam2_from_cam1)
.rotation.toRotationMatrix() *
images[image_id1].GetRAlign())
.col(1));
}

ceres::CostFunction* coor_cost =
Expand Down Expand Up @@ -123,9 +122,8 @@ void GravityRefiner::RefineGravity(const ViewGraph& view_graph,
frames[frame_id].gravity_info.SetGravity(gravity);
}
}
std::cout << std::endl;
LOG(INFO) << "Number of rectified frames: " << counter_rect << " / "
<< error_prone_frames.size() << std::endl;
<< error_prone_frames.size();
}

void GravityRefiner::IdentifyErrorProneGravity(
Expand Down Expand Up @@ -179,7 +177,6 @@ void GravityRefiner::IdentifyErrorProneGravity(
error_prone_frames.insert(frame_id);
}
}
LOG(INFO) << "Number of error prone frames: " << error_prone_frames.size()
<< std::endl;
LOG(INFO) << "Number of error prone frames: " << error_prone_frames.size();
}
} // namespace glomap
4 changes: 1 addition & 3 deletions glomap/io/colmap_converter.cc
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Expand Up @@ -361,7 +361,7 @@ void ConvertDatabaseToGlomap(const colmap::Database& database,

// Initialize the image pair
auto ite = image_pairs.insert(
std::make_pair(ImagePair::ImagePairToPairId(image_id1, image_id2),
std::make_pair(colmap::ImagePairToPairId(image_id1, image_id2),
ImagePair(image_id1, image_id2)));
ImagePair& image_pair = ite.first->second;

Expand Down Expand Up @@ -419,8 +419,6 @@ void ConvertDatabaseToGlomap(const colmap::Database& database,
}
image_pair.matches.conservativeResize(count, 2);
}
std::cout << std::endl;

LOG(INFO) << "Pairs read done. " << invalid_count << " / "
<< view_graph.image_pairs.size() << " are invalid";
}
Expand Down
20 changes: 10 additions & 10 deletions glomap/io/pose_io.cc
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Expand Up @@ -56,7 +56,7 @@ void ReadRelPose(const std::string& file_path,
image_t index1 = name_idx[file1];
image_t index2 = name_idx[file2];

image_pair_t pair_id = ImagePair::ImagePairToPairId(index1, index2);
const image_pair_t pair_id = colmap::ImagePairToPairId(index1, index2);

// rotation
Rigid3d pose_rel;
Expand All @@ -81,7 +81,7 @@ void ReadRelPose(const std::string& file_path,
}
counter++;
}
LOG(INFO) << counter << " relpose are loaded" << std::endl;
LOG(INFO) << counter << " relative poses are loaded";
}

void ReadRelWeight(const std::string& file_path,
Expand Down Expand Up @@ -118,7 +118,7 @@ void ReadRelWeight(const std::string& file_path,
image_t index1 = name_idx[file1];
image_t index2 = name_idx[file2];

image_pair_t pair_id = ImagePair::ImagePairToPairId(index1, index2);
image_pair_t pair_id = colmap::ImagePairToPairId(index1, index2);

if (view_graph.image_pairs.find(pair_id) == view_graph.image_pairs.end())
continue;
Expand All @@ -127,7 +127,7 @@ void ReadRelWeight(const std::string& file_path,
view_graph.image_pairs[pair_id].weight = std::stod(item);
counter++;
}
LOG(INFO) << counter << " weights are used are loaded" << std::endl;
LOG(INFO) << counter << " weights are used are loaded";
}

// TODO: now, we only store 1 single gravity per rig.
Expand Down Expand Up @@ -172,7 +172,7 @@ void ReadGravity(const std::string& gravity_path,
}
}
}
LOG(INFO) << counter << " images are loaded with gravity" << std::endl;
LOG(INFO) << counter << " images are loaded with gravity";
}

void WriteGlobalRotation(const std::string& file_path,
Expand All @@ -185,7 +185,7 @@ void WriteGlobalRotation(const std::string& file_path,
}
}
for (const auto& image_id : existing_images) {
const auto image = images.at(image_id);
const auto& image = images.at(image_id);
if (!image.IsRegistered()) continue;
file << image.file_name;
Rigid3d cam_from_world = image.CamFromWorld();
Expand All @@ -205,8 +205,8 @@ void WriteRelPose(const std::string& file_path,
std::map<std::string, image_pair_t> name_pair;
for (const auto& [pair_id, image_pair] : view_graph.image_pairs) {
if (image_pair.is_valid) {
const auto image1 = images.at(image_pair.image_id1);
const auto image2 = images.at(image_pair.image_id2);
const auto& image1 = images.at(image_pair.image_id1);
const auto& image2 = images.at(image_pair.image_id2);
name_pair[image1.file_name + " " + image2.file_name] = pair_id;
}
}
Expand All @@ -226,6 +226,6 @@ void WriteRelPose(const std::string& file_path,
file << "\n";
}

LOG(INFO) << name_pair.size() << " relpose are written" << std::endl;
LOG(INFO) << name_pair.size() << " relpose are written";
}
} // namespace glomap
} // namespace glomap
2 changes: 1 addition & 1 deletion glomap/processors/image_pair_inliers.cc
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Expand Up @@ -212,4 +212,4 @@ void ImagePairsInlierCount(ViewGraph& view_graph,
}
}

} // namespace glomap
} // namespace glomap
18 changes: 8 additions & 10 deletions glomap/processors/reconstruction_pruning.cc
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Expand Up @@ -23,8 +23,8 @@ image_t PruneWeaklyConnectedImages(std::unordered_map<frame_t, Frame>& frames,
image_t image_id2 = track.observations[j].first;
frame_t frame_id2 = images[image_id2].frame_id;
if (frame_id1 == frame_id2) continue;
image_pair_t pair_id =
ImagePair::ImagePairToPairId(frame_id1, frame_id2);
const image_pair_t pair_id =
colmap::ImagePairToPairId(frame_id1, frame_id2);
if (pair_covisibility_count.find(pair_id) ==
pair_covisibility_count.end()) {
pair_covisibility_count[pair_id] = 1;
Expand All @@ -44,8 +44,7 @@ image_t PruneWeaklyConnectedImages(std::unordered_map<frame_t, Frame>& frames,
// then require each pair to have at least 5 points
if (count >= 5) {
counter++;
image_t image_id1, image_id2;
ImagePair::PairIdToImagePair(pair_id, image_id1, image_id2);
const auto [image_id1, image_id2] = colmap::PairIdToImagePair(pair_id);

if (frame_observation_count[image_id1] < min_num_observations ||
frame_observation_count[image_id2] < min_num_observations)
Expand Down Expand Up @@ -76,10 +75,9 @@ image_t PruneWeaklyConnectedImages(std::unordered_map<frame_t, Frame>& frames,

ViewGraph visibility_graph;
for (auto& [pair_id, image_pair] : visibility_graph_frame.image_pairs) {
frame_t frame_id1, frame_id2;
ImagePair::PairIdToImagePair(pair_id, frame_id1, frame_id2);
image_t image_id1 = frame_id_to_begin_img[frame_id1];
image_t image_id2 = frame_id_to_begin_img[frame_id2];
const auto [frame_id1, frame_id2] = colmap::PairIdToImagePair(pair_id);
const image_t image_id1 = frame_id_to_begin_img[frame_id1];
const image_t image_id2 = frame_id_to_begin_img[frame_id2];
visibility_graph.image_pairs.insert(
std::make_pair(pair_id, ImagePair(image_id1, image_id2)));
visibility_graph.image_pairs[pair_id].weight = image_pair.weight;
Expand All @@ -96,7 +94,7 @@ image_t PruneWeaklyConnectedImages(std::unordered_map<frame_t, Frame>& frames,
if (image_id == begin_image_id || images.find(image_id) == images.end())
continue;
image_pair_t pair_id =
ImagePair::ImagePairToPairId(begin_image_id, image_id);
colmap::ImagePairToPairId(begin_image_id, image_id);
visibility_graph.image_pairs.insert(
std::make_pair(pair_id, ImagePair(begin_image_id, image_id)));

Expand Down Expand Up @@ -132,4 +130,4 @@ image_t PruneWeaklyConnectedImages(std::unordered_map<frame_t, Frame>& frames,
// return visibility_graph.MarkConnectedComponents(images, min_num_images);
}

} // namespace glomap
} // namespace glomap
2 changes: 1 addition & 1 deletion glomap/processors/relpose_filter.cc
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Expand Up @@ -64,4 +64,4 @@ void RelPoseFilter::FilterInlierRatio(ViewGraph& view_graph,
<< " relative poses with inlier ratio < " << min_inlier_ratio;
}

} // namespace glomap
} // namespace glomap
7 changes: 3 additions & 4 deletions glomap/processors/view_graph_manipulation.cc
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Expand Up @@ -17,7 +17,7 @@ image_pair_t ViewGraphManipulater::SparsifyGraph(
// Keep track of chosen edges
std::unordered_set<image_pair_t> chosen_edges;
const std::unordered_map<image_t, std::unordered_set<image_t>>&
adjacency_list = view_graph.GetAdjacencyList();
adjacency_list = view_graph.CreateImageAdjacencyList();

// Here, the average is the mean of the degrees
double average_degree = 0;
Expand Down Expand Up @@ -47,6 +47,7 @@ image_pair_t ViewGraphManipulater::SparsifyGraph(
continue;
}

// TODO: Replace rand() with thread-safe random number generator.
if (rand() / double(RAND_MAX) <
(expected_degree * average_degree) / (degree1 * degree2)) {
chosen_edges.insert(pair_id);
Expand Down Expand Up @@ -208,9 +209,7 @@ void ViewGraphManipulater::UpdateImagePairsConfig(
// pairs are valid, then set the camera to valid
std::unordered_map<camera_t, bool> camera_validity;
for (auto& [camera_id, counter] : camera_counter) {
if (counter.first == 0) {
camera_validity[camera_id] = false;
} else if (counter.second * 1. / counter.first > 0.5) {
if (counter.second * 1. / counter.first > 0.5) {
camera_validity[camera_id] = true;
} else {
camera_validity[camera_id] = false;
Expand Down
44 changes: 14 additions & 30 deletions glomap/scene/image_pair.h
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Expand Up @@ -9,19 +9,24 @@

namespace glomap {

// FUTURE: add covariance to the relative pose
// TODO: add covariance to the relative pose
struct ImagePair {
ImagePair() : pair_id(-1), image_id1(-1), image_id2(-1) {}
ImagePair(image_t img_id1, image_t img_id2, Rigid3d pose_rel = Rigid3d())
: pair_id(ImagePairToPairId(img_id1, img_id2)),
image_id1(img_id1),
image_id2(img_id2),
cam2_from_cam1(pose_rel) {}
ImagePair()
: image_id1(colmap::kInvalidImageId),
image_id2(colmap::kInvalidImageId),
pair_id(colmap::kInvalidImagePairId) {}
ImagePair(image_t image_id1,
image_t image_id2,
Rigid3d cam2_from_cam1 = Rigid3d())
: image_id1(image_id1),
image_id2(image_id2),
pair_id(colmap::ImagePairToPairId(image_id1, image_id2)),
cam2_from_cam1(cam2_from_cam1) {}

// Ids are kept constant
const image_pair_t pair_id;
const image_t image_id1;
const image_t image_id2;
const image_pair_t pair_id;

// indicator whether the image pair is valid
bool is_valid = true;
Expand All @@ -40,7 +45,7 @@ struct ImagePair {
Eigen::Matrix3d H = Eigen::Matrix3d::Zero();

// Relative pose.
Rigid3d cam2_from_cam1;
Rigid3d cam2_from_cam1 = Rigid3d();

// Matches between the two images.
// First column is the index of the feature in the first image.
Expand All @@ -49,27 +54,6 @@ struct ImagePair {

// Row index of inliers in the matches matrix.
std::vector<int> inliers;

static inline image_pair_t ImagePairToPairId(const image_t image_id1,
const image_t image_id2);

static inline void PairIdToImagePair(const image_pair_t pair_id,
image_t& image_id1,
image_t& image_id2);
};

image_pair_t ImagePair::ImagePairToPairId(const image_t image_id1,
const image_t image_id2) {
return colmap::ImagePairToPairId(image_id1, image_id2);
}

void ImagePair::PairIdToImagePair(const image_pair_t pair_id,
image_t& image_id1,
image_t& image_id2) {
std::pair<image_t, image_t> image_id_pair =
colmap::PairIdToImagePair(pair_id);
image_id1 = image_id_pair.first;
image_id2 = image_id_pair.second;
}

} // namespace glomap
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