Projection extension: migrate Assets on Items (stac-utils#1549)

* Migrate projection extension on assets

* Add migrate test for collection item-assets

* Add 1549 to changelog

* Fix asset+item_asset migration handling

Author: bmcandr

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Added
 
+- Projection extension: migrate Assets and Item-Assets ([#1549](https://github.com/stac-utils/pystac/pull/1549))
 - `Collection.from_items` for creating a `pystac.Collection` from an `ItemCollection` ([#1522](https://github.com/stac-utils/pystac/pull/1522))
 - `extensions.mlm` for supporting the [MLM](https://github.com/stac-extensions/mlm) extension ([#1542](https://github.com/stac-utils/pystac/pull/1542))
 

pystac/extensions/projection.py

@@ -480,6 +480,11 @@ def migrate(
         if epsg := obj["properties"].pop("proj:epsg", None):
             obj["properties"]["proj:code"] = f"EPSG:{epsg}"
 
+        for key in ["assets", "item_assets"]:
+            for asset in obj.get(key, {}).values():
+                if epsg := asset.pop("proj:epsg", None):
+                    asset["proj:code"] = f"EPSG:{epsg}"
+
         super().migrate(obj, version, info)
 
 

tests/data-files/projection/collection-with-summaries.json

@@ -20,8 +20,35 @@
       "type": "application/json"
     }
   ],
+  "item_assets": {
+    "analytic": {
+      "type": "image/tiff; application=geotiff; profile=cloud-optimized",
+      "title": "4-Band Analytic",
+      "roles": [
+        "data"
+      ],
+      "gsd": 0.66,
+      "proj:code": "EPSG:32659",
+      "proj:shape": [
+        5558,
+        9559
+      ],
+      "proj:transform": [
+        0.5,
+        0,
+        712710,
+        0,
+        -0.5,
+        151406,
+        0,
+        0,
+        1
+      ]
+    }
+  },
   "stac_extensions": [
-    "https://stac-extensions.github.io/projection/v2.0.0/schema.json"
+    "https://stac-extensions.github.io/projection/v2.0.0/schema.json",
+    "https://stac-extensions.github.io/item-assets/v1.0.0/schema.json"
   ],
   "summaries": {
     "proj:code": [

tests/extensions/test_projection.py

@@ -574,7 +574,7 @@ def test_get_set_code(projection_landsat8_item: Item) -> None:
     assert proj_item.properties["proj:code"] == "IAU_2015:30100"
 
 
-def test_migrate() -> None:
+def test_migrate_item() -> None:
     old = "https://stac-extensions.github.io/projection/v1.1.0/schema.json"
     current = "https://stac-extensions.github.io/projection/v2.0.0/schema.json"
 
@@ -587,6 +587,27 @@ def test_migrate() -> None:
     assert item.ext.proj.epsg == 32614
     assert item.ext.proj.code == "EPSG:32614"
 
+    assert item.assets["B1"].ext.proj.epsg == 32614
+    assert item.assets["B1"].ext.proj.code == "EPSG:32614"
+
+    assert item.assets["B8"].ext.proj.epsg == 9999
+    assert item.assets["B8"].ext.proj.code == "EPSG:9999"
+
+
+def test_migrate_collection_item_assets() -> None:
+    old = "https://stac-extensions.github.io/projection/v1.1.0/schema.json"
+    current = "https://stac-extensions.github.io/projection/v2.0.0/schema.json"
+
+    path = TestCases.get_path("data-files/projection/collection-with-summaries.json")
+    collection = pystac.Collection.from_file(path)
+
+    assert old not in collection.stac_extensions
+    assert current in collection.stac_extensions
+
+    for item_asset in collection.item_assets.values():
+        assert item_asset.ext.proj.epsg == 32659
+        assert item_asset.ext.proj.code == "EPSG:32659"
+
 
 def test_older_extension_version(projection_landsat8_item: Item) -> None:
     old = "https://stac-extensions.github.io/projection/v1.0.0/schema.json"