feat: accept base64 image data URIs

ollama/_types.py

@@ -167,6 +167,16 @@ def serialize_model(self):
       return b64encode(self.value.read_bytes() if isinstance(self.value, Path) else self.value).decode()
 
     if isinstance(self.value, str):
+      if self.value.lower().startswith('data:'):
+        header, separator, encoded = self.value.partition(',')
+        if not separator or not encoded or not header.lower().startswith('data:image/') or not header.lower().endswith(';base64'):
+          raise ValueError('Invalid image data URI, expected a base64-encoded image')
+        try:
+          b64decode(encoded, validate=True)
+        except Exception as exc:
+          raise ValueError('Invalid image data URI, expected a base64-encoded image') from exc
+        return encoded
+
       try:
         if Path(self.value).exists():
           return b64encode(Path(self.value).read_bytes()).decode()

tests/test_image_data_uri.py

@@ -0,0 +1,25 @@
+import base64
+
+import pytest
+
+from ollama._types import Image
+
+
+def test_image_data_uri_serializes_as_base64():
+  encoded = base64.b64encode(b'example image bytes').decode()
+  assert Image(value=f'data:image/png;base64,{encoded}').model_dump() == encoded
+  assert Image(value=f'DATA:IMAGE/PNG;BASE64,{encoded}').model_dump() == encoded
+
+
+@pytest.mark.parametrize(
+  'value',
+  [
+    'data:image/png,not-base64',
+    'data:image/png;base64,invalid!',
+    'data:image/png;base64,',
+    'data:text/plain;base64,ZXhhbXBsZQ==',
+  ],
+)
+def test_invalid_image_data_uri_raises(value: str):
+  with pytest.raises(ValueError, match='Invalid image data URI'):
+    Image(value=value).model_dump()