Issue with Annotation Order in HistomicsUI Interface

[yann2276]

Hello everyone,

I am currently working with HistomicsUI and encountering an issue with the order of annotations. I am sending annotations via the API in a specific order, and they are correctly ordered in the JSON payload. However, once they are displayed in the HistomicsUI interface, the order seems to change.

Here is an example of the JSON payload I am sending:

{
    "image_id": "6888f040a69b227bc43b952f",
    "annotations": {
        "name": "DeepZoide Annotations",
        "description": "Annotations generated by DeepZoide with user corrections (sorted by decreasing confidence)",
        "elements": [
            {
                "type": "rectangle",
                "center": [29680.565673828125, 21630.282348632812, 0],
                "width": 26.0728759765625,
                "height": 16.4754638671875,
                "label": {"value": "spermatozoide (81%)"},
                "user": {"login": "deepzoide_ai", "_id": "ai_detection"}
            },
            {
                "type": "rectangle",
                "center": [35654.292572021484, 8688.458129882812, 0],
                "width": 20.757080078125,
                "height": 20.218017578125,
                "label": {"value": "spermatozoide (78%)"},
                "user": {"login": "deepzoide_ai", "_id": "ai_detection"}
            }
        ]
    }
}

Despite the order in the JSON, the annotations appear differently in the interface.

However, I have noticed that if I manually set the width and height of all annotation elements to the same values (e.g., 80), the display order matches the order in the JSON. This suggests the rendering order might be influenced by the size or position of the annotations.

Is this an intended behavior? Are there any known mechanisms in HistomicsUI that reorder annotations based on their geometry or other metadata?

Is there a better or more reliable way to control the display order of annotations?

Thank you for your help!

Best regards,
Yann

[manthey]

For display, we haven't been considering annotation elements as an ordered list, but as an unordered set. To scale to huge numbers of elements, we query for the elements for the first n elements ordered largest to smallest, but this has been considered an internal implementation detail. Further, we use bulk inserts into the database, which doesn't guarantee any order (since there should be other unique properties).

We'd have to add something to order annotation elements by a property in the HistomicsUI interface. The database API endpoints support ordering them by properties (though I'd have to confirm this could handle arbitrary user data).

[yann2276]

Thanks a lot for the clarification, that helps! I’ll explore sorting via a custom property like order.
Appreciate your input!

Best,
Yann