Handle image mode (#374)

* Handle image mode

Change-Id: Idbd0d65f6359557adbf812190048514080d48e6f

* format

Change-Id: Ia8a386ef959907650dd4fa5b5ab7401e75b9484a

Author: MarkDaoust

Diff for: google/generativeai/types/content_types.py

@@ -72,7 +72,7 @@
 
 def pil_to_blob(img):
     bytesio = io.BytesIO()
-    if isinstance(img, PIL.PngImagePlugin.PngImageFile):
+    if isinstance(img, PIL.PngImagePlugin.PngImageFile) or img.mode == "RGBA":
         img.save(bytesio, format="PNG")
         mime_type = "image/png"
     else:

Diff for: tests/test_content.py

@@ -24,6 +24,7 @@
 import IPython.display
 import PIL.Image
 
+import numpy as np
 
 HERE = pathlib.Path(__file__).parent
 TEST_PNG_PATH = HERE / "test_img.png"
@@ -67,6 +68,7 @@ class ADataClassWithList:
 class UnitTests(parameterized.TestCase):
     @parameterized.named_parameters(
         ["PIL", PIL.Image.open(TEST_PNG_PATH)],
+        ["RGBA", PIL.Image.fromarray(np.zeros([6, 6, 4], dtype=np.uint8))],
         ["IPython", IPython.display.Image(filename=TEST_PNG_PATH)],
     )
     def test_png_to_blob(self, image):
@@ -77,6 +79,7 @@ def test_png_to_blob(self, image):
 
     @parameterized.named_parameters(
         ["PIL", PIL.Image.open(TEST_JPG_PATH)],
+        ["RGB", PIL.Image.fromarray(np.zeros([6, 6, 3], dtype=np.uint8))],
         ["IPython", IPython.display.Image(filename=TEST_JPG_PATH)],
     )
     def test_jpg_to_blob(self, image):