Discussion: classification-based filters for picture description

Hi all — opening a short discussion to explain the motivation behind PR #2836 and get feedback.

In our pipeline we classify pictures (e.g. chart/table/logo/screenshot). We only want to run picture description on a subset of those classes, and optionally enforce a minimum classification confidence.

PR #2836 adds three optional fields to PictureDescriptionBaseOptions:
- classification_allow
- classification_deny
- classification_min_confidence

and uses them to skip describing images that don’t pass the filter. This is especially helpful to avoid expensive descriptions for e.g. logos, screenshots, or low-confidence classifications.

PR: https://github.com/docling-project/docling/pull/2836

Would love feedback on naming, behavior, and whether this belongs in core options. Happy to update docs/tests as needed.