fix(factory.py): get image type from response headers

Fixes https://github.com/BerriAI/litellm/issues/4441

litellm/llms/prompt_templates/factory.py

@@ -663,19 +663,23 @@ def convert_url_to_base64(url):
         image_bytes = response.content
         base64_image = base64.b64encode(image_bytes).decode("utf-8")
 
-        img_type = url.split(".")[-1].lower()
-        if img_type == "jpg" or img_type == "jpeg":
-            img_type = "image/jpeg"
-        elif img_type == "png":
-            img_type = "image/png"
-        elif img_type == "gif":
-            img_type = "image/gif"
-        elif img_type == "webp":
-            img_type = "image/webp"
+        image_type = response.headers.get("Content-Type", None)
+        if image_type is not None and image_type.startswith("image/"):
+            img_type = image_type
         else:
-            raise Exception(
-                f"Error: Unsupported image format. Format={img_type}. Supported types = ['image/jpeg', 'image/png', 'image/gif', 'image/webp']"
-            )
+            img_type = url.split(".")[-1].lower()
+            if img_type == "jpg" or img_type == "jpeg":
+                img_type = "image/jpeg"
+            elif img_type == "png":
+                img_type = "image/png"
+            elif img_type == "gif":
+                img_type = "image/gif"
+            elif img_type == "webp":
+                img_type = "image/webp"
+            else:
+                raise Exception(
+                    f"Error: Unsupported image format. Format={img_type}. Supported types = ['image/jpeg', 'image/png', 'image/gif', 'image/webp']"
+                )
 
         return f"data:{img_type};base64,{base64_image}"
     else:

litellm/tests/test_prompt_factory.py

@@ -1,7 +1,8 @@
 #### What this tests ####
 #    This tests if prompts are being correctly formatted
-import sys
 import os
+import sys
+
 import pytest
 
 sys.path.insert(0, os.path.abspath("../.."))
@@ -10,12 +11,13 @@ sys.path.insert(0, os.path.abspath("../.."))
 import litellm
 from litellm import completion
 from litellm.llms.prompt_templates.factory import (
-    anthropic_pt,
+    _bedrock_tools_pt,
     anthropic_messages_pt,
+    anthropic_pt,
     claude_2_1_pt,
+    convert_url_to_base64,
     llama_2_chat_pt,
     prompt_factory,
-    _bedrock_tools_pt,
 )
 
 
@@ -153,3 +155,11 @@ def test_bedrock_tool_calling_pt():
     converted_tools = _bedrock_tools_pt(tools=tools)
 
     print(converted_tools)
+
+
+def test_convert_url_to_img():
+    response_url = convert_url_to_base64(
+        url="https://images.pexels.com/photos/1319515/pexels-photo-1319515.jpeg?auto=compress&cs=tinysrgb&w=1260&h=750&dpr=1"
+    )
+
+    assert "image/jpeg" in response_url