Add EQUIRECTANGULAR camera model support for 360° images

cmake/FindDependencies.cmake

@@ -20,6 +20,37 @@ if(TESTS_ENABLED)
     find_package(GTest REQUIRED)
 endif()
 
+include(FetchContent)
+
+# Use local PoseLib with EQUIRECTANGULAR support
+FetchContent_Declare(PoseLib
+    SOURCE_DIR        /home/selstad/Desktop/colmap_workspace/PoseLib
+    EXCLUDE_FROM_ALL
+    SYSTEM
+)
+message(STATUS "Configuring PoseLib (local with EQUIRECTANGULAR)...")
+if (FETCH_POSELIB)
+    FetchContent_MakeAvailable(PoseLib)
+else()
+    find_package(PoseLib REQUIRED)
+endif()
+message(STATUS "Configuring PoseLib... done")
+
+# Use local COLMAP with EQUIRECTANGULAR support
+FetchContent_Declare(COLMAP
+    SOURCE_DIR        /home/selstad/Desktop/colmap_workspace/colmap
+    EXCLUDE_FROM_ALL
+)
+message(STATUS "Configuring COLMAP (local with EQUIRECTANGULAR)...")
+set(UNINSTALL_ENABLED OFF CACHE INTERNAL "")
+set(GUI_ENABLED OFF CACHE INTERNAL "")
+if (FETCH_COLMAP)
+    FetchContent_MakeAvailable(COLMAP)
+else()
+    find_package(COLMAP REQUIRED)
+endif()
+message(STATUS "Configuring COLMAP... done")
+
 set(CUDA_MIN_VERSION "7.0")
 if(CUDA_ENABLED)
     if(CMAKE_VERSION VERSION_LESS 3.17)

glomap/estimators/view_graph_calibration.cc

@@ -54,6 +54,10 @@ void ViewGraphCalibrator::Reset(
   focals_.clear();
   focals_.reserve(cameras.size());
   for (const auto& [camera_id, camera] : cameras) {
+    // Skip spherical cameras - they don't have a focal length to estimate
+    if (camera.IsSpherical()) {
+      continue;
+    }
     focals_[camera_id] = camera.Focal();
   }
 
@@ -85,6 +89,12 @@ void ViewGraphCalibrator::AddImagePair(
   const camera_t camera_id1 = images.at(image_pair.image_id1).camera_id;
   const camera_t camera_id2 = images.at(image_pair.image_id2).camera_id;
 
+  // Skip image pairs involving spherical cameras
+  if (cameras.at(camera_id1).IsSpherical() ||
+      cameras.at(camera_id2).IsSpherical()) {
+    return;
+  }
+
   if (camera_id1 == camera_id2) {
     problem_->AddResidualBlock(
         FetzerFocalLengthSameCameraCost::Create(
@@ -123,6 +133,11 @@ void ViewGraphCalibrator::CopyBackResults(
     std::unordered_map<camera_t, Camera>& cameras) {
   size_t counter = 0;
   for (auto& [camera_id, camera] : cameras) {
+    // Skip spherical cameras - they were not optimized
+    if (camera.IsSpherical()) {
+      continue;
+    }
+
     if (!problem_->HasParameterBlock(&(focals_[camera_id]))) continue;
 
     // if the estimated parameter is too crazy, reject it

glomap/scene/camera.h

@@ -20,18 +20,48 @@ struct Camera : public colmap::Camera {
 
   bool has_refined_focal_length = false;
 
+  // Returns true if this is a spherical camera model (e.g., EQUIRECTANGULAR)
+  // Spherical cameras do not have meaningful focal length or principal point
+  inline bool IsSpherical() const;
+
   inline double Focal() const;
   inline Eigen::Vector2d PrincipalPoint() const;
   inline Eigen::Matrix3d GetK() const;
 };
 
-double Camera::Focal() const { return (FocalLengthX() + FocalLengthY()) / 2.0; }
+bool Camera::IsSpherical() const {
+  // Check by model name since model_id may not be defined for EQUIRECTANGULAR
+  // in older COLMAP versions
+  return ModelName() == "EQUIRECTANGULAR" || ModelName() == "SPHERICAL";
+}
+
+double Camera::Focal() const {
+  // Spherical cameras don't have a meaningful focal length
+  // Return a dummy value based on image dimensions for compatibility
+  if (IsSpherical()) {
+    return static_cast<double>(std::max(width, height)) / M_PI;
+  }
+  return (FocalLengthX() + FocalLengthY()) / 2.0;
+}
 
 Eigen::Vector2d Camera::PrincipalPoint() const {
+  // Spherical cameras don't have a principal point in the traditional sense
+  // Return the image center for compatibility
+  if (IsSpherical()) {
+    return Eigen::Vector2d(width / 2.0, height / 2.0);
+  }
   return Eigen::Vector2d(PrincipalPointX(), PrincipalPointY());
 }
 
 Eigen::Matrix3d Camera::GetK() const {
+  // Spherical cameras don't have a 3x3 intrinsic matrix
+  // Return identity-like matrix for compatibility (should not be used)
+  if (IsSpherical()) {
+    Eigen::Matrix3d K = Eigen::Matrix3d::Identity();
+    K(0, 2) = width / 2.0;
+    K(1, 2) = height / 2.0;
+    return K;
+  }
   Eigen::Matrix3d K;
   K << FocalLengthX(), 0, PrincipalPointX(), 0, FocalLengthY(),
       PrincipalPointY(), 0, 0, 1;