Fix datumaro keypoint loading (#1644)

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### Summary

This fixes the bug in loading a keypoint dataset in datumaro format. 
The visibility information will be filled correctly by this fix.

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Resolves #111 and #222.
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- [x] I have added unit tests to cover my changes.​
- [ ] I have added integration tests to cover my changes.​
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License](https://github.com/openvinotoolkit/datumaro/blob/develop/LICENSE)
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# Copyright (C) 2024 Intel Corporation
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# SPDX-License-Identifier: MIT
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CHANGELOG.md

@@ -23,6 +23,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   (<https://github.com/openvinotoolkit/datumaro/pull/1603>)
 
 ### Bug fixes
+- Fix datumaro format to load visibility information from Points annotations
+  (<https://github.com/openvinotoolkit/datumaro/pull/1644>)
 
 ## Q4 2024 Release 1.9.1
 ### Enhancements

src/datumaro/plugins/data_formats/datumaro/base.py

@@ -339,6 +339,7 @@ def _load_annotations(self, item: Dict):
                             points,
                             label=label_id,
                             id=ann_id,
+                            visibility=ann.get("visibility"),
                             attributes=attributes,
                             group=group,
                             object_id=object_id,

tests/unit/data_formats/datumaro/conftest.py

@@ -91,14 +91,15 @@ def fxt_test_datumaro_format_dataset():
                         },
                     ),
                     Points(
-                        [1, 2, 2, 0, 1, 1],
+                        [1, 2, 0, 0, 1, 1],
                         label=0,
                         id=5,
                         z_order=4,
                         attributes={
                             "x": 1,
                             "y": "2",
                         },
+                        visibility=[1, 0, 2],
                     ),
                     Mask(
                         label=3,