Spine 2D Localization
=====================

Summary
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Detects vertebrae and other key structures in X-Ray (2D) images using learned models, and can construct an `ASCSet` and `SpineData` from detections and optional segmentations—use for analyzing single-frame or multi-frame X-Ray images to obtain landmarks.

See also: :doc:`SpineData <../SpineData>`.

Compatible data
----------------
- Requires: `SharedImageSet` (single image or multi-frame set).
- Implicit assumptions: sufficient image quality/contrast for the selected model set; correct frame orientation.

Output
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- Detections (keypoints), optional segmentations for sacrum/femurs/clavicles.
- `ASCSet` and `SpineData` assembled from detected elements.

Key parameters
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- `splitVertebrae` (bool): If false, keypoints are added globally; if true, associated per-vertebra.
- `modelSet` (string), `modelSetVersion` (string): Select the model set combination.

Workflow
--------
1) Load/select an X-Ray image or sequence.
2) Choose a model set and version; adjust split behavior.
3) Run localization; review detections and constructed `SpineData`/`ASCSet`.

Notes
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- Keypoint association handles some missing/mirrored keypoints and still forms vertebra entries in typical patterns.
- Multi-frame inputs are supported; ensure correct frame selection/iteration in the UI.