add imagecodec example

Author: d-v-b

examples/image_codec.py

@@ -0,0 +1,51 @@
+# /// script
+# requires-python = ">=3.11"
+# dependencies = [
+#   "zarr @ git+https://github.com/zarr-developers/zarr-python.git@main",
+#   "imagecodecs==2025.3.30",
+#   "pytest==8.4.2"
+# ]
+# ///
+
+from typing import Literal
+
+import numcodecs
+import numpy as np
+import pytest
+from imagecodecs.numcodecs import Jpeg
+
+import zarr
+from zarr.core.common import ZarrFormat
+
+numcodecs.register_codec(Jpeg)
+jpg_codec = Jpeg()
+
+
+@pytest.mark.parametrize("zarr_format", ZarrFormat)
+def test(zarr_format: Literal[2, 3]) -> None:
+    store = {}
+    if zarr_format == 2:
+        z_w = zarr.create_array(
+            store=store,
+            data=np.zeros((100, 100, 3), dtype=np.uint8),
+            compressors=jpg_codec,
+            zarr_format=zarr_format,
+        )
+    else:
+        z_w = zarr.create_array(
+            store=store,
+            data=np.zeros((100, 100, 3), dtype=np.uint8),
+            serializer=jpg_codec,
+            zarr_format=zarr_format,
+        )
+    z_w[:] = 2
+    z_r = zarr.open_array(store=store, zarr_format=zarr_format)
+    assert np.all(z_r[:] == 2)
+    if zarr_format == 2:
+        print(z_r.metadata.to_dict()["compressor"])
+    else:
+        print(z_r.metadata.to_dict()["codecs"])
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, f"-c {__file__}", "-s"])