Visualize Objectron Dataset with Rerun

How to visualize the Google Research Objectron Dataset including camera poses, sparse point-clouds and surfaces characterization

Andreas Naoum
Rerun-io
2 min readMay 14, 2024

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Short Object Centric Video with Pose Annotations in Rerun | Image by Author

This example visualizes the Objectron database, a rich collection of object-centric video clips accompanied by AR session metadata. With high-resolution images, object pose, camera pose, point-cloud, and surface plane information available for each sample, the visualization offers a comprehensive view of the object from various angles. Additionally, the dataset provides manually annotated 3D bounding boxes, enabling precise object localization and orientation.

Logging and visualizing with Rerun

The visualizations in this example were created with the following Rerun code:

Timelines

For each processed frame, all data sent to Rerun is associated with the two timelines time and frame_idx.

rr.set_time_sequence("frame", sample.index)
rr.set_time_seconds("time", sample.timestamp)

Video

Pinhole camera is utilized for achieving a 3D view and camera perspective through the use of the Pinhole and Transform3D archetypes.

rr.log(
"world/camera",
rr.Transform3D(translation=translation, rotation=rr.Quaternion(xyzw=rot.as_quat())),
)
rr.log(
"world/camera",
rr.Pinhole(
resolution=[w, h],
image_from_camera=intrinsics,
camera_xyz=rr.ViewCoordinates.RDF,
),
)

The input video is logged as a sequence of ImageEncoded objects to the world/camera entity.

rr.log("world/camera", rr.ImageEncoded(path=sample.image_path))

Sparse point clouds

Sparse point clouds from ARFrame are logged as Points3D archetype to the world/points entity.

rr.log("world/points", rr.Points3D(positions, colors=[255, 255, 255, 255]))

Annotated bounding boxes

Bounding boxes annotated from ARFrame are logged as Boxes3D, containing details such as object position, sizes, center and rotation.

rr.log(
f"world/annotations/box-{bbox.id}",
rr.Boxes3D(
half_sizes=0.5 * np.array(bbox.scale),
centers=bbox.translation,
rotations=rr.Quaternion(xyzw=rot.as_quat()),
colors=[160, 230, 130, 255],
labels=bbox.category,
),
timeless=True,
)

Setting up the default blueprint

The default blueprint is configured with the following code:

blueprint = rrb.Horizontal(
rrb.Spatial3DView(origin="/world", name="World"),
rrb.Spatial2DView(origin="/world/camera", name="Camera", contents=["/world/**"]),
)

In particular, we want to reproject the points and the 3D annotation box in the 2D camera view corresponding to the pinhole logged at “/world/camera”. This is achieved by setting the view’s contents to the entire “/world/**” subtree, which include both the pinhole transform and the image data, as well as the point cloud and the 3D annotation box.

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Andreas Naoum
Rerun-io

AI | Robotics | Apple Enthusiast | Passionate Computer Scientist pursuing an MSc in Autonomous Systems at KTH.