Update api.py

api.py

@@ -240,7 +240,7 @@ def display_gradcam(img, heatmap, alpha=0.4):
     return base64.b64encode(img_byte_arr).decode('utf-8')
 
 
-def calculate_activation_ratio(heatmap, threshold=0.45):
+def calculate_activation_ratio(heatmap, threshold=0.2):
   """Calculates the ratio of activated to non-activated pixels in a heatmap.
 
   Args: