From 2d087402207cf94081ce3996b4c08f3d014d2a0e Mon Sep 17 00:00:00 2001
From: Nicola Loi <nicolaloi@outlook.com>
Date: Sat, 2 Nov 2024 12:05:53 +0100
Subject: [PATCH 1/2] Add select_by_index method to Feature class
---
CHANGELOG.md | 1 +
cpp/open3d/pipelines/registration/Feature.cpp | 25 +++++++++++++++
cpp/open3d/pipelines/registration/Feature.h | 8 +++++
cpp/pybind/pipelines/registration/feature.cpp | 10 ++++++
.../t/pipelines/registration/Feature.cpp | 32 +++++++++++++++++++
5 files changed, 76 insertions(+)
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7fb1cf1e1aa..efc11e57ef5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -51,6 +51,7 @@
- Fix tensor EstimatePointWiseNormalsWithFastEigen3x3 (PR #6980)
- Fix alpha shape reconstruction if alpha too small for point scale (PR #6998)
- Fix render to depth image on Apple Retina displays (PR #7001)
+- Add select_by_index method to Feature class (PR #7039)
## 0.13
diff --git a/cpp/open3d/pipelines/registration/Feature.cpp b/cpp/open3d/pipelines/registration/Feature.cpp
index 41b036ebbab..e45f5672d9d 100644
--- a/cpp/open3d/pipelines/registration/Feature.cpp
+++ b/cpp/open3d/pipelines/registration/Feature.cpp
@@ -18,6 +18,31 @@ namespace open3d {
namespace pipelines {
namespace registration {
+std::shared_ptr<Feature> Feature::SelectByIndex(
+ const std::vector<size_t> &indices, bool invert) const {
+ auto output = std::make_shared<Feature>();
+ output->Resize(data_.rows(), indices.size());
+
+ std::vector<bool> mask = std::vector<bool>(data_.cols(), invert);
+ for (size_t i : indices) {
+ mask[i] = !invert;
+ }
+
+ size_t current_col_feature = 0;
+ for (size_t i = 0; i < static_cast<size_t>(data_.cols()); i++) {
+ if (mask[i]) {
+ output->data_.col(current_col_feature) = data_.col(i);
+ current_col_feature++;
+ }
+ }
+
+ utility::LogDebug(
+ "Feature group down sampled from {:d} features to {:d} features.",
+ (int)data_.cols(), (int)output->data_.cols());
+
+ return output;
+}
+
static Eigen::Vector4d ComputePairFeatures(const Eigen::Vector3d &p1,
const Eigen::Vector3d &n1,
const Eigen::Vector3d &p2,
diff --git a/cpp/open3d/pipelines/registration/Feature.h b/cpp/open3d/pipelines/registration/Feature.h
index 41bb4776a35..f4d9630688d 100644
--- a/cpp/open3d/pipelines/registration/Feature.h
+++ b/cpp/open3d/pipelines/registration/Feature.h
@@ -42,6 +42,14 @@ class Feature {
/// Returns number of points.
size_t Num() const { return data_.cols(); }
+ /// \brief Selects features from \p input Feature group, with indices in \p
+ /// indices, and returns a new Feature group with selected features.
+ ///
+ /// \param indices Indices of features to be selected.
+ /// \param invert Set to `True` to invert the selection of indices.
+ std::shared_ptr<Feature> SelectByIndex(const std::vector<size_t> &indices,
+ bool invert = false) const;
+
public:
/// Data buffer storing features.
Eigen::MatrixXd data_;
diff --git a/cpp/pybind/pipelines/registration/feature.cpp b/cpp/pybind/pipelines/registration/feature.cpp
index ce298dceec3..fd40b5b5f94 100644
--- a/cpp/pybind/pipelines/registration/feature.cpp
+++ b/cpp/pybind/pipelines/registration/feature.cpp
@@ -31,6 +31,11 @@ void pybind_feature_definitions(py::module &m_registration) {
.def("dimension", &Feature::Dimension,
"Returns feature dimensions per point.")
.def("num", &Feature::Num, "Returns number of points.")
+ .def("select_by_index", &Feature::SelectByIndex,
+ "Function to select features from input Feature group into "
+ "output "
+ "Feature group.",
+ "indices"_a, "invert"_a = false)
.def_readwrite("data", &Feature::data_,
"``dim x n`` float64 numpy array: Data buffer "
"storing features.")
@@ -48,6 +53,11 @@ void pybind_feature_definitions(py::module &m_registration) {
docstring::ClassMethodDocInject(m_registration, "Feature", "resize",
{{"dim", "Feature dimension per point."},
{"n", "Number of points."}});
+ docstring::ClassMethodDocInject(
+ m_registration, "Feature", "select_by_index",
+ {{"indices", "Indices of features to be selected."},
+ {"invert",
+ "Set to ``True`` to invert the selection of indices."}});
m_registration.def("compute_fpfh_feature", &ComputeFPFHFeature,
"Function to compute FPFH feature for a point cloud",
"input"_a, "search_param"_a);
diff --git a/cpp/tests/t/pipelines/registration/Feature.cpp b/cpp/tests/t/pipelines/registration/Feature.cpp
index b636b8cd516..d4adc0958b3 100644
--- a/cpp/tests/t/pipelines/registration/Feature.cpp
+++ b/cpp/tests/t/pipelines/registration/Feature.cpp
@@ -25,6 +25,38 @@ INSTANTIATE_TEST_SUITE_P(Feature,
FeaturePermuteDevices,
testing::ValuesIn(PermuteDevices::TestCases()));
+TEST_P(FeaturePermuteDevices, SelectByIndex) {
+ core::Device device = GetParam();
+
+ open3d::geometry::PointCloud pcd_legacy;
+ data::BunnyMesh bunny;
+ open3d::io::ReadPointCloud(bunny.GetPath(), pcd_legacy);
+
+ pcd_legacy.EstimateNormals();
+ // Convert to float64 to avoid precision loss.
+ const auto pcd = t::geometry::PointCloud::FromLegacy(pcd_legacy,
+ core::Float64, device);
+
+ const auto fpfh = pipelines::registration::ComputeFPFHFeature(
+ pcd_legacy, geometry::KDTreeSearchParamHybrid(0.01, 100));
+ const auto fpfh_t =
+ t::pipelines::registration::ComputeFPFHFeature(pcd, 100, 0.01);
+
+ const auto selected_fpfh =
+ fpfh->SelectByIndex({53, 194, 839, 2543, 6391, 29483}, false);
+ const auto selected_indeces_t =
+ core::TensorKey::IndexTensor(core::Tensor::Init<int64_t>(
+ {53, 194, 839, 2543, 6391, 29483}, device));
+ const auto selected_fpfh_t = fpfh_t.GetItem(selected_indeces_t);
+
+ EXPECT_TRUE(selected_fpfh_t.AllClose(
+ core::eigen_converter::EigenMatrixToTensor(selected_fpfh->data_)
+ .T()
+ .To(selected_fpfh_t.GetDevice(),
+ selected_fpfh_t.GetDtype()),
+ 1e-4, 1e-4));
+}
+
TEST_P(FeaturePermuteDevices, ComputeFPFHFeature) {
core::Device device = GetParam();
From 2870c69dc6544c7e970dc05b8081fab08317fb23 Mon Sep 17 00:00:00 2001
From: Nicola Loi <nicolaloi@outlook.com>
Date: Sun, 3 Nov 2024 11:30:09 +0100
Subject: [PATCH 2/2] better comments
---
cpp/open3d/pipelines/registration/Feature.cpp | 2 +-
cpp/pybind/pipelines/registration/feature.cpp | 3 +--
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/cpp/open3d/pipelines/registration/Feature.cpp b/cpp/open3d/pipelines/registration/Feature.cpp
index e45f5672d9d..c43adbd585f 100644
--- a/cpp/open3d/pipelines/registration/Feature.cpp
+++ b/cpp/open3d/pipelines/registration/Feature.cpp
@@ -19,7 +19,7 @@ namespace pipelines {
namespace registration {
std::shared_ptr<Feature> Feature::SelectByIndex(
- const std::vector<size_t> &indices, bool invert) const {
+ const std::vector<size_t> &indices, bool invert /* = false */) const {
auto output = std::make_shared<Feature>();
output->Resize(data_.rows(), indices.size());
diff --git a/cpp/pybind/pipelines/registration/feature.cpp b/cpp/pybind/pipelines/registration/feature.cpp
index fd40b5b5f94..4baef5b560c 100644
--- a/cpp/pybind/pipelines/registration/feature.cpp
+++ b/cpp/pybind/pipelines/registration/feature.cpp
@@ -33,8 +33,7 @@ void pybind_feature_definitions(py::module &m_registration) {
.def("num", &Feature::Num, "Returns number of points.")
.def("select_by_index", &Feature::SelectByIndex,
"Function to select features from input Feature group into "
- "output "
- "Feature group.",
+ "output Feature group.",
"indices"_a, "invert"_a = false)
.def_readwrite("data", &Feature::data_,
"``dim x n`` float64 numpy array: Data buffer "