initial

app.py

@@ -113,7 +113,7 @@ def detect_features(image_paths):
     except Exception as e:
         print(e.__class__, e)
         traceback.print_exc()
-        return None, None
+        return "", []
 
 
 def generate(features, image, structure, reference, model, temperature):
@@ -121,8 +121,8 @@ def generate(features, image, structure, reference, model, temperature):
     image_features, base64_images = detect_features(image)
     detected_features = ""
     intended_use = ""
-    alt_texts = ""
-    if image_features is not None:
+    alt_texts = []
+    if image_features is not None and len(image_features) > 0:
         alt_texts = image_features["alt_text"]
         detected_features = ", ".join(image_features["features"])
         intended_use = "Intended use: " + ", ".join(image_features["intended_use"])