fix(demo): clear stale classification overlay after tracking loss

opengait/demo/pipeline.py

@@ -438,18 +438,22 @@ class ScoliosisPipeline:
                             copy_method = cast(
                                 Callable[[], object] | None, getattr(v, "copy", None)
                             )
-                            if copy_method is not None:
+                            if copy_method is not None and callable(copy_method):
                                 cached[k] = copy_method()
                             else:
                                 cached[k] = v
                         self._last_viz_payload = cached
 
-                    # Use cached payload if current is None
+                    if viz_payload is not None:
-                    viz_data = (
+                        viz_data = viz_payload
-                        viz_payload
+                    elif self._last_viz_payload is not None:
-                        if viz_payload is not None
+                        viz_data = dict(self._last_viz_payload)
-                        else self._last_viz_payload
+                        viz_data["bbox"] = None
-                    )
+                        viz_data["bbox_mask"] = None
+                        viz_data["label"] = None
+                        viz_data["confidence"] = None
+                    else:
+                        viz_data = None
 
                     if viz_data is not None:
                         # Cast viz_payload to dict for type checking

tests/demo/test_pipeline.py

@@ -790,12 +790,7 @@ def test_pipeline_visualizer_updates_on_no_detection() -> None:
             assert call["confidence"] is None  # No confidence when no detection
 
 
-def test_pipeline_visualizer_uses_cached_detection_on_no_detection() -> None:
+def test_pipeline_visualizer_clears_bbox_on_no_detection() -> None:
-    """Test that visualizer reuses last valid detection when current frame has no detection.
-
-    This is a regression test for the cache-reuse behavior when person temporarily
-    disappears from frame. The last valid silhouette/mask should be displayed.
-    """
     from opengait.demo.pipeline import ScoliosisPipeline
 
     # Create a minimal pipeline with mocked dependencies
@@ -884,7 +879,6 @@ def test_pipeline_visualizer_uses_cached_detection_on_no_detection() -> None:
         assert mask_raw_calls[0] is not None, "Frame 0 should have valid mask"
         assert mask_raw_calls[1] is not None, "Frame 1 should have valid mask"
 
-        # Frames 2 and 3 should reuse the cached mask from frame 1 (not None)
         assert mask_raw_calls[2] is not None, (
             "Frame 2 (no detection) should display cached mask from last valid detection, "
             "not None/blank"
@@ -902,10 +896,21 @@ def test_pipeline_visualizer_uses_cached_detection_on_no_detection() -> None:
         assert segmentation_inputs[1] is not None
         assert segmentation_inputs[2] is not None
         assert segmentation_inputs[3] is not None
+        bbox_calls = [call["bbox"] for call in mock_viz.update_calls]
+        assert bbox_calls[0] == dummy_bbox_frame
+        assert bbox_calls[1] == dummy_bbox_frame
+        assert bbox_calls[2] is None
+        assert bbox_calls[3] is None
         assert bbox_mask_calls[0] == dummy_bbox_mask
         assert bbox_mask_calls[1] == dummy_bbox_mask
-        assert bbox_mask_calls[2] == dummy_bbox_mask
+        assert bbox_mask_calls[2] is None
-        assert bbox_mask_calls[3] == dummy_bbox_mask
+        assert bbox_mask_calls[3] is None
+        label_calls = [call["label"] for call in mock_viz.update_calls]
+        confidence_calls = [call["confidence"] for call in mock_viz.update_calls]
+        assert label_calls[2] is None
+        assert label_calls[3] is None
+        assert confidence_calls[2] is None
+        assert confidence_calls[3] is None
 
         if mask_raw_calls[1] is not None and mask_raw_calls[2] is not None:
             assert mask_raw_calls[1] is not mask_raw_calls[2], (