SegmentationMetrics
===================

Segmentation quality metrics computation.

Computes Dice coefficient, Hausdorff distance, and other metrics for
comparing test segmentations against reference (gold standard) segmentations.

Classes
-------

.. py:class:: MetricsResult

   Result of comparing two segmentations.

   **Methods:**

   .. py:method:: to_dict()

      Convert to dictionary for JSON serialization.


.. py:class:: SegmentationMetrics

   Compute comparison metrics between segmentations.
   
   Uses SimpleITK for Dice, Hausdorff, and overlap metrics.
   
   Usage:
       metrics = SegmentationMetrics.compute(
           test_seg_node, test_segment_id,
           ref_seg_node, ref_segment_id,
           volume_node
       )
       print(f"Dice: {metrics.dice:.3f}")
       print(f"Hausdorff 95%: {metrics.hausdorff_95:.1f}mm")

   **Methods:**

   .. py:method:: compute()

      Compute Dice and Hausdorff between test and reference segmentations.

   .. py:method:: compute_dice_only()

      Compute Dice coefficient only (faster than full metrics).


.. py:class:: StrokeRecord

   Record of a single stroke's metrics.

   **Methods:**

   .. py:method:: to_dict()

      Convert to dictionary for JSON serialization.


.. py:class:: StrokeMetricsTracker

   Track how metrics improve with each stroke.
   
   Usage:
       tracker = StrokeMetricsTracker(gold_seg, gold_id, volume)
   
       for stroke_params in stroke_list:
           # Apply stroke to test_seg...
           record = tracker.record_stroke(test_seg, test_id, stroke_params)
           print(f"Stroke {record.stroke}: Dice={record.dice:.3f}")
   
       summary = tracker.get_summary()
       print(f"Strokes to 90% Dice: {summary['strokes_to_90pct']}")

   **Methods:**

   .. py:method:: __init__()

      Initialize tracker.

   .. py:method:: record_stroke()

      Record metrics after a stroke.

   .. py:method:: get_summary()

      Summarize stroke progression.

   .. py:method:: reset()

      Clear stroke history for a new trial.


Functions
---------

.. py:function:: to_dict()

   Convert to dictionary for JSON serialization.

.. py:function:: compute()

   Compute Dice and Hausdorff between test and reference segmentations.
   
   Args:
       test_seg_node: Test segmentation MRML node.
       test_segment_id: Segment ID within test segmentation.
       reference_seg_node: Reference (gold) segmentation MRML node.
       reference_segment_id: Segment ID within reference segmentation.
       volume_node: Volume node providing geometry (spacing).
   
   Returns:
       MetricsResult with all computed metrics.

.. py:function:: compute_dice_only()

   Compute Dice coefficient only (faster than full metrics).
   
   Args:
       test_seg_node: Test segmentation MRML node.
       test_segment_id: Segment ID within test segmentation.
       reference_seg_node: Reference (gold) segmentation MRML node.
       reference_segment_id: Segment ID within reference segmentation.
       volume_node: Volume node providing geometry.
   
   Returns:
       Dice coefficient (0-1).

.. py:function:: to_dict()

   Convert to dictionary for JSON serialization.

.. py:function:: record_stroke()

   Record metrics after a stroke.
   
   Args:
       test_seg_node: Test segmentation MRML node.
       test_segment_id: Segment ID within test segmentation.
       stroke_params: Parameters used for this stroke.
   
   Returns:
       StrokeRecord with computed metrics.

.. py:function:: get_summary()

   Summarize stroke progression.
   
   Returns:
       Dictionary with summary statistics.

.. py:function:: reset()

   Clear stroke history for a new trial.