Next batch of changes to support the vision code on the orin

Set up separate camera1 and camera2 data streams.
This includes both argus_camera and april tag detection

Enable channel selection for foxglove image converter

Build and deploy viewer app

Compile multi-camera calibration

Change-Id: I976f7b7594903d632c7481b06784d03c2c05190e
Signed-off-by: Jim Ostrowski <yimmy13@gmail.com>
diff --git a/y2024/vision/calibrate_multi_cameras.cc b/y2024/vision/calibrate_multi_cameras.cc
new file mode 100644
index 0000000..9148217
--- /dev/null
+++ b/y2024/vision/calibrate_multi_cameras.cc
@@ -0,0 +1,709 @@
+#include <numeric>
+
+#include "aos/configuration.h"
+#include "aos/events/logging/log_reader.h"
+#include "aos/events/simulated_event_loop.h"
+#include "aos/init.h"
+#include "aos/util/mcap_logger.h"
+#include "frc971/control_loops/pose.h"
+#include "frc971/control_loops/quaternion_utils.h"
+#include "frc971/vision/calibration_generated.h"
+#include "frc971/vision/charuco_lib.h"
+#include "frc971/vision/extrinsics_calibration.h"
+#include "frc971/vision/target_mapper.h"
+#include "frc971/vision/visualize_robot.h"
+// clang-format off
+// OpenCV eigen files must be included after Eigen includes
+#include "opencv2/aruco.hpp"
+#include "opencv2/calib3d.hpp"
+#include "opencv2/core/eigen.hpp"
+#include "opencv2/features2d.hpp"
+#include "opencv2/highgui.hpp"
+#include "opencv2/highgui/highgui.hpp"
+#include "opencv2/imgproc.hpp"
+// clang-format on
+#include "frc971/constants/constants_sender_lib.h"
+#include "frc971/vision/vision_util_lib.h"
+#include "y2024/constants/simulated_constants_sender.h"
+#include "y2024/vision/vision_util.h"
+
+DEFINE_bool(alt_view, false,
+            "If true, show visualization from field level, rather than above");
+DEFINE_string(config, "",
+              "If set, override the log's config file with this one.");
+DEFINE_string(constants_path, "y2023/constants/constants.json",
+              "Path to the constant file");
+DEFINE_double(max_pose_error, 5e-5,
+              "Throw out target poses with a higher pose error than this");
+DEFINE_double(
+    max_pose_error_ratio, 0.4,
+    "Throw out target poses with a higher pose error ratio than this");
+DEFINE_string(output_folder, "/tmp",
+              "Directory in which to store the updated calibration files");
+DEFINE_string(target_type, "charuco_diamond",
+              "Type of target being used [aruco, charuco, charuco_diamond]");
+DEFINE_int32(team_number, 0,
+             "Required: Use the calibration for a node with this team number");
+DEFINE_bool(use_full_logs, false,
+            "If true, extract data from logs with images");
+DEFINE_uint64(
+    wait_key, 1,
+    "Time in ms to wait between images (0 to wait indefinitely until click)");
+
+DECLARE_int32(min_target_id);
+DECLARE_int32(max_target_id);
+
+// Calibrate extrinsic relationship between cameras using two targets
+// seen jointly between cameras.  Uses two types of information: 1)
+// when a single camera sees two targets, we estimate the pose between
+// targets, and 2) when two separate cameras each see a target, we can
+// use the pose between targets to estimate the pose between cameras.
+
+// We then create the extrinsics for the robot by starting with the
+// given extrinsic for camera 1 (between imu/robot and camera frames)
+// and then map each subsequent camera based on the data collected and
+// the extrinsic poses computed here.
+
+// TODO<Jim>: Not currently using estimate from pi1->pi4-- should do full
+// estimation, and probably also include camera->imu extrinsics from all
+// cameras, not just pi1
+
+namespace y2023::vision {
+using frc971::vision::DataAdapter;
+using frc971::vision::ImageCallback;
+using frc971::vision::PoseUtils;
+using frc971::vision::TargetMap;
+using frc971::vision::TargetMapper;
+using frc971::vision::VisualizeRobot;
+namespace calibration = frc971::vision::calibration;
+
+static constexpr double kImagePeriodMs =
+    1.0 / 30.0 * 1000.0;  // Image capture period in ms
+
+// Change reference frame from camera to robot
+Eigen::Affine3d CameraToRobotDetection(Eigen::Affine3d H_camera_target,
+                                       Eigen::Affine3d extrinsics) {
+  const Eigen::Affine3d H_robot_camera = extrinsics;
+  const Eigen::Affine3d H_robot_target = H_robot_camera * H_camera_target;
+  return H_robot_target;
+}
+
+struct TimestampedPiDetection {
+  aos::distributed_clock::time_point time;
+  // Pose of target relative to robot
+  Eigen::Affine3d H_camera_target;
+  // name of pi
+  std::string pi_name;
+  int board_id;
+};
+
+TimestampedPiDetection last_observation;
+std::vector<std::pair<TimestampedPiDetection, TimestampedPiDetection>>
+    detection_list;
+std::vector<TimestampedPiDetection> two_board_extrinsics_list;
+VisualizeRobot vis_robot_;
+
+// TODO<jim>: Implement variance calcs
+Eigen::Affine3d ComputeAveragePose(
+    std::vector<Eigen::Vector3d> &translation_list,
+    std::vector<Eigen::Vector4d> &rotation_list,
+    Eigen::Vector3d *translation_variance = nullptr,
+    Eigen::Vector3d *rotation_variance = nullptr) {
+  Eigen::Vector3d avg_translation =
+      std::accumulate(translation_list.begin(), translation_list.end(),
+                      Eigen::Vector3d{0, 0, 0}) /
+      translation_list.size();
+
+  // TODO<Jim>: Use QuaternionMean from quaternion_utils.cc (but this
+  // requires a fixed number of quaternions to be averaged
+  Eigen::Vector4d avg_rotation =
+      std::accumulate(rotation_list.begin(), rotation_list.end(),
+                      Eigen::Vector4d{0, 0, 0, 0}) /
+      rotation_list.size();
+  // Normalize, so it's a valid quaternion
+  avg_rotation = avg_rotation / avg_rotation.norm();
+  Eigen::Quaterniond avg_rotation_q{avg_rotation[0], avg_rotation[1],
+                                    avg_rotation[2], avg_rotation[3]};
+  Eigen::Translation3d translation(avg_translation);
+  Eigen::Affine3d return_pose = translation * avg_rotation_q;
+  if (translation_variance != nullptr) {
+    *translation_variance = Eigen::Vector3d();
+  }
+  if (rotation_variance != nullptr) {
+    LOG(INFO) << *rotation_variance;
+  }
+
+  return return_pose;
+}
+
+Eigen::Affine3d ComputeAveragePose(
+    std::vector<Eigen::Affine3d> &pose_list,
+    Eigen::Vector3d *translation_variance = nullptr,
+    Eigen::Vector3d *rotation_variance = nullptr) {
+  std::vector<Eigen::Vector3d> translation_list;
+  std::vector<Eigen::Vector4d> rotation_list;
+
+  for (Eigen::Affine3d pose : pose_list) {
+    translation_list.push_back(pose.translation());
+    Eigen::Quaterniond quat(pose.rotation().matrix());
+    rotation_list.push_back(
+        Eigen::Vector4d(quat.w(), quat.x(), quat.y(), quat.z()));
+  }
+
+  return ComputeAveragePose(translation_list, rotation_list,
+                            translation_variance, rotation_variance);
+}
+
+Eigen::Affine3d ComputeAveragePose(
+    std::vector<TimestampedPiDetection> &pose_list,
+    Eigen::Vector3d *translation_variance = nullptr,
+    Eigen::Vector3d *rotation_variance = nullptr) {
+  std::vector<Eigen::Vector3d> translation_list;
+  std::vector<Eigen::Vector4d> rotation_list;
+
+  for (TimestampedPiDetection pose : pose_list) {
+    translation_list.push_back(pose.H_camera_target.translation());
+    Eigen::Quaterniond quat(pose.H_camera_target.rotation().matrix());
+    rotation_list.push_back(
+        Eigen::Vector4d(quat.w(), quat.x(), quat.y(), quat.z()));
+  }
+  return ComputeAveragePose(translation_list, rotation_list,
+                            translation_variance, rotation_variance);
+}
+
+void HandlePoses(cv::Mat rgb_image,
+                 std::vector<TargetMapper::TargetPose> target_poses,
+                 aos::distributed_clock::time_point distributed_eof,
+                 std::string node_name) {
+  // This is used to transform points for visualization
+  // Assumes targets are aligned with x->right, y->up, z->out of board
+  Eigen::Affine3d H_world_board;
+  H_world_board = Eigen::Translation3d::Identity() *
+                  Eigen::AngleAxisd(M_PI / 2.0, Eigen::Vector3d::UnitX());
+  if (FLAGS_alt_view) {
+    // Don't rotate -- this is like viewing from the side
+    H_world_board = Eigen::Translation3d(0.0, 0.0, 3.0);
+  }
+
+  bool draw_vis = false;
+  CHECK_LE(target_poses.size(), 2u)
+      << "Can't handle more than two tags in field of view";
+  if (target_poses.size() == 2) {
+    draw_vis = true;
+    VLOG(1) << "Saw two boards in same view from " << node_name;
+    int from_index = 0;
+    int to_index = 1;
+    // Handle when we see two boards at once
+    // We'll store them referenced to the lower id board
+    if (target_poses[from_index].id > target_poses[to_index].id) {
+      std::swap<int>(from_index, to_index);
+    }
+
+    // Create "from" (A) and "to" (B) transforms
+    Eigen::Affine3d H_camera_boardA =
+        PoseUtils::Pose3dToAffine3d(target_poses[from_index].pose);
+    Eigen::Affine3d H_camera_boardB =
+        PoseUtils::Pose3dToAffine3d(target_poses[to_index].pose);
+
+    Eigen::Affine3d H_boardA_boardB =
+        H_camera_boardA.inverse() * H_camera_boardB;
+
+    TimestampedPiDetection boardA_boardB{
+        .time = distributed_eof,
+        .H_camera_target = H_boardA_boardB,
+        .pi_name = node_name,
+        .board_id = target_poses[from_index].id};
+
+    VLOG(1) << "Map from board " << from_index << " to " << to_index << " is\n"
+            << H_boardA_boardB.matrix();
+    // Store this observation of the transform between two boards
+    two_board_extrinsics_list.push_back(boardA_boardB);
+
+    if (FLAGS_visualize) {
+      vis_robot_.DrawFrameAxes(
+          H_world_board,
+          std::string("board ") + std::to_string(target_poses[from_index].id),
+          cv::Scalar(0, 255, 0));
+      vis_robot_.DrawFrameAxes(
+          H_world_board * boardA_boardB.H_camera_target,
+          std::string("board ") + std::to_string(target_poses[to_index].id),
+          cv::Scalar(255, 0, 0));
+      VLOG(2) << "Detection map from camera " << node_name << " to board "
+              << target_poses[from_index].id << " is\n"
+              << H_camera_boardA.matrix() << "\n and inverse is\n"
+              << H_camera_boardA.inverse().matrix()
+              << "\n and with world to board rotation is\n"
+              << H_world_board * H_camera_boardA.inverse().matrix();
+      vis_robot_.DrawRobotOutline(H_world_board * H_camera_boardA.inverse(),
+                                  node_name, cv::Scalar(0, 0, 255));
+    }
+  } else if (target_poses.size() == 1) {
+    VLOG(1) << "Saw single board in camera " << node_name;
+    Eigen::Affine3d H_camera2_board2 =
+        PoseUtils::Pose3dToAffine3d(target_poses[0].pose);
+    TimestampedPiDetection new_observation{.time = distributed_eof,
+                                           .H_camera_target = H_camera2_board2,
+                                           .pi_name = node_name,
+                                           .board_id = target_poses[0].id};
+
+    // Only take two observations if they're within half an image cycle of each
+    // other (i.e., as close in time as possible)
+    if (std::abs((distributed_eof - last_observation.time).count()) <
+        kImagePeriodMs / 2.0 * 1000000.0) {
+      // Sort by pi numbering, since this is how we will handle them
+      std::pair<TimestampedPiDetection, TimestampedPiDetection> new_pair;
+      if (last_observation.pi_name < new_observation.pi_name) {
+        new_pair = std::pair(last_observation, new_observation);
+      } else if (last_observation.pi_name > new_observation.pi_name) {
+        new_pair = std::pair(new_observation, last_observation);
+      } else {
+        LOG(WARNING) << "Got 2 observations in a row from same pi. Probably "
+                        "not too much of an issue???";
+      }
+      detection_list.push_back(new_pair);
+
+      // This bit is just for visualization and checking purposes-- use the
+      // last two-board observation to figure out the current estimate
+      // between the two cameras
+      if (FLAGS_visualize && two_board_extrinsics_list.size() > 0) {
+        draw_vis = true;
+        TimestampedPiDetection &last_two_board_ext =
+            two_board_extrinsics_list[two_board_extrinsics_list.size() - 1];
+        Eigen::Affine3d &H_boardA_boardB = last_two_board_ext.H_camera_target;
+        int boardA_boardB_id = last_two_board_ext.board_id;
+
+        TimestampedPiDetection camera1_boardA = new_pair.first;
+        TimestampedPiDetection camera2_boardB = new_pair.second;
+        // If camera1_boardA doesn't point to the first target, then swap
+        // these two
+        if (camera1_boardA.board_id != boardA_boardB_id) {
+          camera1_boardA = new_pair.second;
+          camera2_boardB = new_pair.first;
+        }
+        VLOG(1) << "Camera " << camera1_boardA.pi_name << " seeing board "
+                << camera1_boardA.board_id << " and camera "
+                << camera2_boardB.pi_name << " seeing board "
+                << camera2_boardB.board_id;
+
+        vis_robot_.DrawRobotOutline(
+            H_world_board * camera1_boardA.H_camera_target.inverse(),
+            camera1_boardA.pi_name, cv::Scalar(0, 0, 255));
+        vis_robot_.DrawRobotOutline(
+            H_world_board * H_boardA_boardB *
+                camera2_boardB.H_camera_target.inverse(),
+            camera2_boardB.pi_name, cv::Scalar(128, 128, 0));
+        vis_robot_.DrawFrameAxes(
+            H_world_board,
+            std::string("Board ") + std::to_string(last_two_board_ext.board_id),
+            cv::Scalar(0, 255, 0));
+        vis_robot_.DrawFrameAxes(H_world_board * H_boardA_boardB, "Board B",
+                                 cv::Scalar(255, 0, 0));
+      }
+      VLOG(1) << "Storing observation between " << new_pair.first.pi_name
+              << ", target " << new_pair.first.board_id << " and "
+              << new_pair.second.pi_name << ", target "
+              << new_pair.second.board_id;
+    } else {
+      VLOG(2) << "Storing observation for " << node_name << " at time "
+              << distributed_eof;
+      last_observation = new_observation;
+    }
+  }
+
+  if (FLAGS_visualize) {
+    if (!rgb_image.empty()) {
+      std::string image_name = node_name + " Image";
+      cv::Mat rgb_small;
+      cv::resize(rgb_image, rgb_small, cv::Size(), 0.5, 0.5);
+      cv::imshow(image_name, rgb_small);
+      cv::waitKey(FLAGS_wait_key);
+    }
+
+    if (draw_vis) {
+      cv::imshow("View", vis_robot_.image_);
+      cv::waitKey(FLAGS_wait_key);
+      vis_robot_.ClearImage();
+    }
+  }
+}
+
+void HandleTargetMap(const TargetMap &map,
+                     aos::distributed_clock::time_point distributed_eof,
+                     std::string node_name) {
+  VLOG(1) << "Got april tag map call from node " << node_name;
+  // Create empty RGB image in this case
+  cv::Mat rgb_image;
+  std::vector<TargetMapper::TargetPose> target_poses;
+
+  for (const auto *target_pose_fbs : *map.target_poses()) {
+    // Skip detections with invalid ids
+    if (static_cast<TargetMapper::TargetId>(target_pose_fbs->id()) <
+            FLAGS_min_target_id ||
+        static_cast<TargetMapper::TargetId>(target_pose_fbs->id()) >
+            FLAGS_max_target_id) {
+      LOG(INFO) << "Skipping tag with invalid id of " << target_pose_fbs->id();
+      continue;
+    }
+
+    // Skip detections with high pose errors
+    if (target_pose_fbs->pose_error() > FLAGS_max_pose_error) {
+      LOG(INFO) << "Skipping tag " << target_pose_fbs->id()
+                << " due to pose error of " << target_pose_fbs->pose_error();
+      continue;
+    }
+    // Skip detections with high pose error ratios
+    if (target_pose_fbs->pose_error_ratio() > FLAGS_max_pose_error_ratio) {
+      LOG(INFO) << "Skipping tag " << target_pose_fbs->id()
+                << " due to pose error ratio of "
+                << target_pose_fbs->pose_error_ratio();
+      continue;
+    }
+
+    const TargetMapper::TargetPose target_pose =
+        PoseUtils::TargetPoseFromFbs(*target_pose_fbs);
+
+    target_poses.emplace_back(target_pose);
+
+    Eigen::Affine3d H_camera_target =
+        PoseUtils::Pose3dToAffine3d(target_pose.pose);
+    VLOG(2) << node_name << " saw target " << target_pose.id
+            << " from TargetMap at timestamp " << distributed_eof
+            << " with pose = " << H_camera_target.matrix();
+  }
+  HandlePoses(rgb_image, target_poses, distributed_eof, node_name);
+}
+
+void HandleImage(aos::EventLoop *event_loop, cv::Mat rgb_image,
+                 const aos::monotonic_clock::time_point eof,
+                 aos::distributed_clock::time_point distributed_eof,
+                 frc971::vision::CharucoExtractor &charuco_extractor,
+                 std::string node_name) {
+  std::vector<cv::Vec4i> charuco_ids;
+  std::vector<std::vector<cv::Point2f>> charuco_corners;
+  bool valid = false;
+  std::vector<Eigen::Vector3d> rvecs_eigen;
+  std::vector<Eigen::Vector3d> tvecs_eigen;
+  // Why eof vs. distributed_eof?
+  charuco_extractor.ProcessImage(rgb_image, eof, event_loop->monotonic_now(),
+                                 charuco_ids, charuco_corners, valid,
+                                 rvecs_eigen, tvecs_eigen);
+  if (rvecs_eigen.size() > 0 && !valid) {
+    LOG(WARNING) << "Charuco extractor returned not valid";
+    return;
+  }
+
+  std::vector<TargetMapper::TargetPose> target_poses;
+  for (size_t i = 0; i < tvecs_eigen.size(); i++) {
+    Eigen::Quaterniond rotation(
+        frc971::controls::ToQuaternionFromRotationVector(rvecs_eigen[i]));
+    ceres::examples::Pose3d pose(Eigen::Vector3d(tvecs_eigen[i]), rotation);
+    TargetMapper::TargetPose target_pose{charuco_ids[i][0], pose};
+    target_poses.emplace_back(target_pose);
+
+    Eigen::Affine3d H_camera_target = PoseUtils::Pose3dToAffine3d(pose);
+    VLOG(2) << node_name << " saw target " << target_pose.id
+            << " from image at timestamp " << distributed_eof
+            << " with pose = " << H_camera_target.matrix();
+  }
+  HandlePoses(rgb_image, target_poses, distributed_eof, node_name);
+}
+
+void ExtrinsicsMain(int argc, char *argv[]) {
+  vis_robot_ = VisualizeRobot(cv::Size(1000, 1000));
+  vis_robot_.ClearImage();
+  const double kFocalLength = 1000.0;
+  const int kImageWidth = 1000;
+  vis_robot_.SetDefaultViewpoint(kImageWidth, kFocalLength);
+
+  std::optional<aos::FlatbufferDetachedBuffer<aos::Configuration>> config =
+      (FLAGS_config.empty()
+           ? std::nullopt
+           : std::make_optional(aos::configuration::ReadConfig(FLAGS_config)));
+
+  // open logfiles
+  aos::logger::LogReader reader(
+      aos::logger::SortParts(aos::logger::FindLogs(argc, argv)),
+      config.has_value() ? &config->message() : nullptr);
+
+  constexpr size_t kNumPis = 4;
+  for (size_t i = 1; i <= kNumPis; i++) {
+    reader.RemapLoggedChannel(absl::StrFormat("/pi%u/constants", i),
+                              "y2023.Constants");
+  }
+
+  reader.RemapLoggedChannel("/imu/constants", "y2023.Constants");
+  reader.RemapLoggedChannel("/logger/constants", "y2023.Constants");
+  reader.RemapLoggedChannel("/roborio/constants", "y2023.Constants");
+  reader.Register();
+
+  y2024::SendSimulationConstants(reader.event_loop_factory(), FLAGS_team_number,
+                                 FLAGS_constants_path);
+
+  VLOG(1) << "Using target type " << FLAGS_target_type;
+  std::vector<std::string> node_list;
+  node_list.push_back("pi1");
+  node_list.push_back("pi2");
+  node_list.push_back("pi3");
+  node_list.push_back("pi4");
+  std::vector<const calibration::CameraCalibration *> calibration_list;
+
+  std::vector<std::unique_ptr<aos::EventLoop>> detection_event_loops;
+  std::vector<frc971::vision::CharucoExtractor *> charuco_extractors;
+  std::vector<frc971::vision::ImageCallback *> image_callbacks;
+  std::vector<Eigen::Affine3d> default_extrinsics;
+
+  for (uint i = 0; i < node_list.size(); i++) {
+    std::string node = node_list[i];
+    const aos::Node *pi =
+        aos::configuration::GetNode(reader.configuration(), node.c_str());
+
+    detection_event_loops.emplace_back(
+        reader.event_loop_factory()->MakeEventLoop(
+            (node + "_detection").c_str(), pi));
+
+    frc971::constants::ConstantsFetcher<y2024::Constants> constants_fetcher(
+        detection_event_loops.back().get());
+
+    const calibration::CameraCalibration *calibration =
+        y2024::vision::FindCameraCalibration(constants_fetcher.constants(),
+                                             node);
+    calibration_list.push_back(calibration);
+
+    frc971::vision::TargetType target_type =
+        frc971::vision::TargetTypeFromString(FLAGS_target_type);
+    frc971::vision::CharucoExtractor *charuco_ext =
+        new frc971::vision::CharucoExtractor(calibration, target_type);
+    charuco_extractors.emplace_back(charuco_ext);
+
+    cv::Mat extrinsics_cv =
+        frc971::vision::CameraExtrinsics(calibration).value();
+    Eigen::Matrix4d extrinsics_matrix;
+    cv::cv2eigen(extrinsics_cv, extrinsics_matrix);
+    const auto ext_H_robot_pi = Eigen::Affine3d(extrinsics_matrix);
+    default_extrinsics.emplace_back(ext_H_robot_pi);
+
+    VLOG(1) << "Got extrinsics for " << node << " as\n"
+            << default_extrinsics.back().matrix();
+
+    if (FLAGS_use_full_logs) {
+      LOG(INFO) << "Set up image callback for node " << node_list[i];
+      frc971::vision::ImageCallback *image_callback =
+          new frc971::vision::ImageCallback(
+              detection_event_loops[i].get(), "/" + node_list[i] + "/camera",
+              [&reader, &charuco_extractors, &detection_event_loops, &node_list,
+               i](cv::Mat rgb_image,
+                  const aos::monotonic_clock::time_point eof) {
+                aos::distributed_clock::time_point pi_distributed_time =
+                    reader.event_loop_factory()
+                        ->GetNodeEventLoopFactory(
+                            detection_event_loops[i].get()->node())
+                        ->ToDistributedClock(eof);
+                HandleImage(detection_event_loops[i].get(), rgb_image, eof,
+                            pi_distributed_time, *charuco_extractors[i],
+                            node_list[i]);
+              });
+
+      image_callbacks.emplace_back(image_callback);
+    } else {
+      detection_event_loops[i]->MakeWatcher(
+          "/camera", [&reader, &detection_event_loops, &node_list,
+                      i](const TargetMap &map) {
+            aos::distributed_clock::time_point pi_distributed_time =
+                reader.event_loop_factory()
+                    ->GetNodeEventLoopFactory(detection_event_loops[i]->node())
+                    ->ToDistributedClock(aos::monotonic_clock::time_point(
+                        aos::monotonic_clock::duration(
+                            map.monotonic_timestamp_ns())));
+
+            HandleTargetMap(map, pi_distributed_time, node_list[i]);
+          });
+      LOG(INFO) << "Created watcher for using the detection event loop for "
+                << node_list[i] << " with i = " << i << " and size "
+                << detection_event_loops.size();
+    }
+  }
+
+  reader.event_loop_factory()->Run();
+
+  // Do quick check to see what averaged two-board pose for each pi is
+  // individually
+  CHECK_GT(two_board_extrinsics_list.size(), 0u)
+      << "Must have at least one view of both boards";
+  int base_target_id = two_board_extrinsics_list[0].board_id;
+  VLOG(1) << "Base id for two_board_extrinsics_list is " << base_target_id;
+  for (auto node : node_list) {
+    std::vector<TimestampedPiDetection> pose_list;
+    for (auto ext : two_board_extrinsics_list) {
+      CHECK_EQ(base_target_id, ext.board_id)
+          << " All boards should have same reference id";
+      if (ext.pi_name == node) {
+        pose_list.push_back(ext);
+      }
+    }
+    Eigen::Affine3d avg_pose_from_pi = ComputeAveragePose(pose_list);
+    VLOG(1) << "Estimate from " << node << " with " << pose_list.size()
+            << " observations is:\n"
+            << avg_pose_from_pi.matrix();
+  }
+  Eigen::Affine3d H_boardA_boardB_avg =
+      ComputeAveragePose(two_board_extrinsics_list);
+  // TODO: Should probably do some outlier rejection
+  LOG(INFO) << "Estimate of two board pose using all nodes with "
+            << two_board_extrinsics_list.size() << " observations is:\n"
+            << H_boardA_boardB_avg.matrix() << "\n";
+
+  // Next, compute the relative camera poses
+  LOG(INFO) << "Got " << detection_list.size() << " extrinsic observations";
+  std::vector<Eigen::Affine3d> H_camera1_camera2_list;
+  std::vector<Eigen::Affine3d> updated_extrinsics;
+  // Use the first node's extrinsics as our base, and fix from there
+  updated_extrinsics.push_back(default_extrinsics[0]);
+  LOG(INFO) << "Default extrinsic for node " << node_list[0] << " is "
+            << default_extrinsics[0].matrix();
+  for (uint i = 0; i < node_list.size() - 1; i++) {
+    H_camera1_camera2_list.clear();
+    // Go through the list, and find successive pairs of cameras
+    for (auto [pose1, pose2] : detection_list) {
+      if ((pose1.pi_name == node_list[i]) &&
+          (pose2.pi_name == node_list[i + 1])) {
+        Eigen::Affine3d H_camera1_boardA = pose1.H_camera_target;
+        // If pose1 isn't referenced to base_target_id, correct that
+        if (pose1.board_id != base_target_id) {
+          // pose1.H_camera_target references boardB, so map back to boardA
+          H_camera1_boardA =
+              pose1.H_camera_target * H_boardA_boardB_avg.inverse();
+        }
+
+        // Now, get the camera2->boardA map (notice it's boardA, same as
+        // camera1, so we can compute the difference based both on boardA)
+        Eigen::Affine3d H_camera2_boardA = pose2.H_camera_target;
+        // If pose2 isn't referenced to boardA (base_target_id), correct
+        // that
+        if (pose2.board_id != base_target_id) {
+          // pose2.H_camera_target references boardB, so map back to boardA
+          H_camera2_boardA =
+              pose2.H_camera_target * H_boardA_boardB_avg.inverse();
+        }
+
+        // Compute camera1->camera2 map
+        Eigen::Affine3d H_camera1_camera2 =
+            H_camera1_boardA * H_camera2_boardA.inverse();
+        H_camera1_camera2_list.push_back(H_camera1_camera2);
+        VLOG(1) << "Map from camera " << pose1.pi_name << " and tag "
+                << pose1.board_id << " with observation: \n"
+                << pose1.H_camera_target.matrix() << "\n to camera "
+                << pose2.pi_name << " and tag " << pose2.board_id
+                << " with observation: \n"
+                << pose2.H_camera_target.matrix() << "\ngot map as\n"
+                << H_camera1_camera2.matrix();
+
+        Eigen::Affine3d H_world_board;
+        H_world_board = Eigen::Translation3d::Identity() *
+                        Eigen::AngleAxisd(M_PI / 2.0, Eigen::Vector3d::UnitX());
+        if (FLAGS_alt_view) {
+          H_world_board = Eigen::Translation3d(0.0, 0.0, 3.0);
+        }
+
+        VLOG(2) << "Camera1 " << pose1.pi_name << " in world frame is \n"
+                << (H_world_board * H_camera1_boardA.inverse()).matrix();
+        VLOG(2) << "Camera2 " << pose2.pi_name << " in world frame is \n"
+                << (H_world_board * H_camera2_boardA.inverse()).matrix();
+      }
+    }
+    // TODO<Jim>: If we don't get any matches, we could just use default
+    // extrinsics
+    CHECK(H_camera1_camera2_list.size() > 0)
+        << "Failed with zero poses for node " << node_list[i];
+    if (H_camera1_camera2_list.size() > 0) {
+      Eigen::Affine3d H_camera1_camera2_avg =
+          ComputeAveragePose(H_camera1_camera2_list);
+      LOG(INFO) << "From " << node_list[i] << " to " << node_list[i + 1]
+                << " found " << H_camera1_camera2_list.size()
+                << " observations, and the average pose is:\n"
+                << H_camera1_camera2_avg.matrix();
+      Eigen::Affine3d H_camera1_camera2_default =
+          default_extrinsics[i].inverse() * default_extrinsics[i + 1];
+      LOG(INFO) << "Compare this to that from default values:\n"
+                << H_camera1_camera2_default.matrix();
+      Eigen::Affine3d H_camera1_camera2_diff =
+          H_camera1_camera2_avg * H_camera1_camera2_default.inverse();
+      LOG(INFO)
+          << "Difference between averaged and default delta poses "
+             "has |T| = "
+          << H_camera1_camera2_diff.translation().norm() << "m and |R| = "
+          << Eigen::AngleAxisd(H_camera1_camera2_diff.rotation()).angle()
+          << " radians ("
+          << Eigen::AngleAxisd(H_camera1_camera2_diff.rotation()).angle() *
+                 180.0 / M_PI
+          << " degrees)";
+      // Next extrinsic is just previous one * avg_delta_pose
+      Eigen::Affine3d next_extrinsic =
+          updated_extrinsics.back() * H_camera1_camera2_avg;
+      updated_extrinsics.push_back(next_extrinsic);
+      LOG(INFO) << "Default Extrinsic for " << node_list[i + 1] << " is \n"
+                << default_extrinsics[i + 1].matrix();
+      LOG(INFO) << "--> Updated Extrinsic for " << node_list[i + 1] << " is \n"
+                << next_extrinsic.matrix();
+
+      // Wirte out this extrinsic to a file
+      flatbuffers::FlatBufferBuilder fbb;
+      flatbuffers::Offset<flatbuffers::Vector<float>> data_offset =
+          fbb.CreateVector(
+              frc971::vision::MatrixToVector(next_extrinsic.matrix()));
+      calibration::TransformationMatrix::Builder matrix_builder(fbb);
+      matrix_builder.add_data(data_offset);
+      flatbuffers::Offset<calibration::TransformationMatrix>
+          extrinsic_calibration_offset = matrix_builder.Finish();
+
+      calibration::CameraCalibration::Builder calibration_builder(fbb);
+      calibration_builder.add_fixed_extrinsics(extrinsic_calibration_offset);
+      const aos::realtime_clock::time_point realtime_now =
+          aos::realtime_clock::now();
+      calibration_builder.add_calibration_timestamp(
+          realtime_now.time_since_epoch().count());
+      fbb.Finish(calibration_builder.Finish());
+      aos::FlatbufferDetachedBuffer<calibration::CameraCalibration>
+          solved_extrinsics = fbb.Release();
+
+      aos::FlatbufferDetachedBuffer<
+          frc971::vision::calibration::CameraCalibration>
+          cal_copy = aos::RecursiveCopyFlatBuffer(calibration_list[i + 1]);
+      cal_copy.mutable_message()->clear_fixed_extrinsics();
+      cal_copy.mutable_message()->clear_calibration_timestamp();
+      aos::FlatbufferDetachedBuffer<calibration::CameraCalibration>
+          merged_calibration = aos::MergeFlatBuffers(
+              &cal_copy.message(), &solved_extrinsics.message());
+
+      std::stringstream time_ss;
+      time_ss << realtime_now;
+
+      // Assumes node_list name is of form "pi#" to create camera id
+      const std::string calibration_filename =
+          FLAGS_output_folder +
+          absl::StrFormat("/calibration_pi-%d-%s_cam-%s_%s.json",
+                          FLAGS_team_number, node_list[i + 1].substr(2, 3),
+                          calibration_list[i + 1]->camera_id()->data(),
+                          time_ss.str());
+
+      LOG(INFO) << calibration_filename << " -> "
+                << aos::FlatbufferToJson(merged_calibration,
+                                         {.multi_line = true});
+
+      aos::util::WriteStringToFileOrDie(
+          calibration_filename,
+          aos::FlatbufferToJson(merged_calibration, {.multi_line = true}));
+    }
+  }
+
+  // Cleanup
+  for (uint i = 0; i < image_callbacks.size(); i++) {
+    delete charuco_extractors[i];
+    delete image_callbacks[i];
+  }
+}
+}  // namespace y2023::vision
+
+int main(int argc, char **argv) {
+  aos::InitGoogle(&argc, &argv);
+  y2023::vision::ExtrinsicsMain(argc, argv);
+}