README.md

---
language:
- en
size_categories:
- 10K<n<100K
---
# Asset Inspection Dataset

This dataset's scenes are arranged as follows:

  ```
  scene/
  ├── cam_parameters.tar
  ├── depths.tar
  ├── images.tar
  ├── scene.glb Scene 
  └── scene.blend
  ```

The office building scene has four surface soiling settings, so it is arranged as follows

  ```
  office_building
  ├── cam_parameters.tar
  ├── depths.tar
  ├── high_soiling_images.tar
  ├── low_soiling_images.tar
  ├── medium_soiling_images.tar
  ├── office_building.glb
  ├── very_low_soiling_images.tar
  └── Office_model.blend
  ```

## Images

`images.tar` files and `*_images.tar` contain the images in the dataset. Noise _has_ been added - refer to the paper for details on our additive noise model. The images in the bridge and crane scenes are .pngs and office building images are .jpgs to save space.

## Depth Maps

`depths` contains the depth maps. These are .exr files which store the metric depth. Each pixel has a three values each of which is the depth. To open a .exr file, one can use the [OpenEXR](https://openexr.com/en/latest/) python library or the image viewer [tev](https://github.com/Tom94/tev). A function for opening .exr files using OpenEXR in python is included below :

``` python
import OpenEXR

def open_exr(f_name: str):
    with OpenEXR.File(f_name) as infile:
        header = infile.header()
        channels = infile.channels()
        keys = list(channels.keys())
        if keys == ["RGB"]:
            img = channels["RGB"].pixels
        if keys == ["RGBA"]:
            img = channels["RGBA"].pixels
        elif keys == ["X", "Y", "Z"]:
            X = channels["X"].pixels
            Y = channels["Y"].pixels
            Z = channels["Z"].pixels

            height, width = Z.shape

            img = np.empty((height, width, 3))
            img[..., 0] = X
            img[..., 1] = Y
            img[..., 2] = Z

    return img, header
```

Each pixel of the depth map contains the metric depth in each of the three channels. Therefore, if we return to the previous code and `img[..., 0]` will get the depth for each pixel in the image.

## Camera Intrinsics and Extrinsics

Camera intrinsics and extrinsics for each frame are included in `cam_parameters`. Each frame number has an individual .json file which is formatted as follows:

``` json
{
 "loc": [
  world_x_position,
  world_y_position,
  world_z_position
 ],
 "rot": [
    w,
    x,
    y,
    z
 ],
 "focal_length": f_mm,
 "sensor_width": sensor_width_mm,
 "clip_end": max_dist_m,
 "clip_start": min_dist_m
}
```

The `loc` field refers to the position of the camera in the blender world coordinate frame. The `rot` field refers to the rotation quaternion in the blender world coordinate frame (in scalar first format (w, x, y, z)). `focal_length` refers to the focal length of the camera in millimetres. `sensor_width` refers to the width of the camera sensor in mm. `clip_start` and `clip_end` are the minimum and maximum distance settings that blender renders.

To convert these coordinates into the familiar COLMAP coordinate system, one can use the following lines of code:

``` python
  from scipy.spatial.transform import Rotation

colmap_rot = [rot[1], rot[0],
              rot[3], -rot[2]]
colmap_transform = Rotation.from_quat(colmap_rot, scalar_first=True)
T_vec = -colmap_transform.apply(loc)
```

## Mesh model

For each scene, we exported a mesh model. To produce a ground truth point cloud, we sampled the mesh using [Open3D](https://www.open3d.org/). To replicate this, one can use:

```python
import open3d as o3d

mesh = o3d.io.read_triangle_mesh(glb_file_path)
pointcloud_sampled = mesh.sample_points_uniformly(
    number_of_points=1000000)
```

## Blender Scenes

These blender scenes were constructed in [Blender 5.0.1](https://www.blender.org/) from assets from [BlenderKit](https://www.blenderkit.com). To render the office building with different soiling settings, use the `render_office.py` script which can be done using Blender's in built scripting capability or with the following shell command:

``` bash
blender -b Office_model.blend --python render_office.py 
```

### Sources for Blender Assets

We used the following assets in our dataset (some of them substantially modified):

1. Mirazev, A.: Model: Modern Building. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/bab4567f-7f71-44f7-af6b-96f5d60cb66e/>, last accessed 09 Mar 2026
2. Jacinto, M., Pinto, J., Patrikar, J., Keller, J., Cunha, R., Scherer, S., Pascoal, A.: Pegasus Simulator: An Isaac Sim Framework for Multiple Aerial Vehicles Simulation. In: 2024 International Conference on Unmanned Aircraft Systems (ICUAS), pp. 1–8. IEEE (2024). <https://doi.org/10.1109/ICUAS60882.2024.10556959>
3. Se-Cam, J.: Model: 80s Cartoon Wagon Car. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/5150ca16-f5c0-49e9-b2a4-bdf9d6a51e1a/>, last accessed 09 Mar 2026
4. Se-Cam, J.: Model: Cartoon Car / Toy Car. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/b24f0fab-da30-4a85-bdec-c3b2fced3bb7/>, last accessed 09 Mar 2026
5. Se-Cam, J.: Model: 80s Cartoon Pick-Up. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/c587fce1-af5a-4f77-9e78-af10526cf4a5/>, last accessed 09 Mar 2026
6. Tirindelli, D.: Model: 6kw Solar Panels Structure. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/ba8093b7-416c-461c-af22-ac311df86b03/>, last accessed 09 Mar 2026
7. Rexodus: Model: Antenna. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/c67c9184-3ebd-4809-adf5-91b1dd0ae759/>, last accessed 09 Mar 2026
8. Mitroi, R.: Model: AC Unit Big. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/1a06752c-d093-474a-b870-a011deb2366e/>, last accessed 09 Mar 2026
9. Wells, C.: Material: Procedural Concrete Tiles. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/3b90f722-6d01-4f62-be56-f392e9312bac/>, last accessed 09 Mar 2026
10. Paludo, L.: Material: Simple Concrete Procedural. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/6156591b-e7a4-4aee-a6cc-0380517e4003/>, last accessed 09 Mar 2026
11. Share Textures: Material: Dark Steel. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/f170e0bf-f784-482e-86eb-1d7e307a22cc/>, last accessed 09 Mar 2026
12. Michaud, A.: Material: Textured Painted Wall (Procedural). BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/9891df1f-b429-461a-bc5e-b0520e25a120/>, last accessed 09 Mar 2026
13. Yang, R.: Material: White Wall 02. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/9891df1f-b429-461a-bc5e-b0520e25a120/>, last accessed 09 Mar 2026
14. Adhe, E.: Material: Black Painted Plaster Wall. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/61c2c84d-1701-4b19-9728-f0710bab1cce/>, last accessed 09 Mar 2026
15. Pambudi, R.R.: Material: Material Window Glass Cycle. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/4367fa4b-9633-48a2-862f-224fbf7b1730/>, last accessed 09 Mar 2026
16. Yang, R.: HDRi: Urban City Highsky Bluesky. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/139e9edb-ba7f-4848-b6c5-3b5c227ca805/>, last accessed 09 Mar 2026
asset-gallery-detail/aa82da45-2e29-4e4d-9ec4-631977b4d29b/>
17. Cosmo: Model: Suspension/Arch Bridge. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/5358ddd3-6dbf-4a1c-8731-4c6bdcfa8338/>, last accessed 09 Mar 2026
18. MapacheDRelease: Model: Crane Tower. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/eb5c137e-007e-485b-bbb9-675e76fcdac9/>, last accessed 09 Mar 2026
19. Mohammadi, S.: Material: Realistic Procedural Grass (Cycles/Eevee). BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/a465bd1e-a14d-442f-90b4-0bfb02dffa9f/>, last accessed 09 Mar 2026
20. Godoi, M.: Material: Procedural Concrete. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/6312d40c-7afb-49e3-b167-c772147ce40d/>, last accessed 09 Mar 2026
21. Russo 3D: Material: Procedural Brick. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/f5ab3780-1489-4c62-8050-b400bbd14e95/>, last accessed 09 Mar 2026
22. Middleton, J.: Material: Bricks Procedural Wall. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/fa2d62e6-fc17-4310-a0bf-b35eaefcfd3c/>, last accessed 09 Mar 2026
23. Middleton, J.: Material: Brick Wall Procedural. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/79f3e321-4923-45dd-8508-8082163db23d/>, last accessed 09 Mar 2026
24. FreePoly: HDRi: Over The Construction Site Yellow Mud. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/66411e15-4a1f-46cb-8e3a-0271e83dc8e4/>, last accessed 09 Mar 2026
25. FreePoly: HDRi: Lake Highsky Blue Sky. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/aa82da45-2e29-4e4d-9ec4-631977b4d29b/>, last accessed 09 Mar 2026
26. NK Productions: Material: Asphalt Road Procedural. BlenderKit, <https://www.blenderkit.com/asset-gallery-detail/0f2ec127-987c-49ab-9478-7f777bdde2d3/>, last accessed 09 Mar 2026

NB. [2] was used for it's drone model.