Handling 'point_cloud' Field in JSON Export Without Images: Import Error in Datumaro

[ainayves]

Hello, dear developers of Datumaro,

First, thank you for Datumaro, which I recently started using and find very interesting.

I have a question that has been on my mind for a few days.

Here are the steps I followed:

1. Exporting a dataset from CVAT in Datumaro format without requiring the corresponding images to be re-downloaded.

2. Running the following commands:

   datum project create
datum project import -f datumaro <path to the JSON file>

3. I then encountered the following error:

datumaro.components.errors.MediaTypeError: Unexpected media type of a dataset '<class 'datumaro.components.media.Image'>'.
Expected media type is '<class 'datumaro.components.media.PointCloud'>.

4. Upon investigation, I found that the JSON file includes a "point_cloud" field when exporting without images and when the image has no annotations.

  "items": [
    {
      "id": "1713265728.502414164",
      "annotations": [],
      "attr": {
        "frame": 0
      },
      "point_cloud": {
        "path": ""
      }
    }
]
....

5. I manually removed all "point_cloud" fields to make the import work.

My question is : Is there a way to automatically ignore the "point_cloud" field when using Datumaro? Or should I always manually remove it in cases of export without images? Alternatively, could you suggest a different approach?

Note : Sometimes, datasets annotated in CVAT can include thousands of images, so re-downloading them would be a huge time drain.

Thanks in advance for your help, and thank you again for this tool.