diff --git a/hiking_assistant/app.py b/hiking_assistant/app.py
index ce68a28..55cad1b 100644
--- a/hiking_assistant/app.py
+++ b/hiking_assistant/app.py
@@ -3,7 +3,6 @@
 # author: deng
 # date: 20251127
 
-import base64
 from datetime import datetime
 
 import streamlit as st
@@ -12,6 +11,7 @@ from elevation import ElevationRenderer
 from gpx import GPXProcessor
 from map import MapRenderer
 from streamlit_folium import st_folium
+from utils import convert_image_to_base64
 from weather import WeatherFetcher
 
 
@@ -23,17 +23,13 @@ class HikingAssistant:
         with open('assets/config.yaml', 'r') as f:
             return yaml.safe_load(f)
 
-    def _convert_image_to_base64(self, image_path):
-        with open(image_path, 'rb') as f:
-            return base64.b64encode(f.read()).decode()
-
     def _set_page_background(self, image_path, opacity=0.8):
         """Set background image for the application.
 
         Args:
             image_path: Path to the background image
         """
-        image_data = self._convert_image_to_base64(image_path)
+        image_data = convert_image_to_base64(image_path)
         ext = image_path.split('.')[-1]
         overlay = f'rgba(255, 255, 255, {1 - opacity})'
         st.markdown(
@@ -51,7 +47,7 @@ class HikingAssistant:
         )
 
     def _add_custom_title(self, title, image_path):
-        favicon_data = self._convert_image_to_base64(image_path)
+        favicon_data = convert_image_to_base64(image_path)
         ext = image_path.split('.')[-1]
         st.markdown(
             f"""
diff --git a/hiking_assistant/utils.py b/hiking_assistant/utils.py
new file mode 100644
index 0000000..c46b20c
--- /dev/null
+++ b/hiking_assistant/utils.py
@@ -0,0 +1,14 @@
+# utils.py
+#
+# author: deng
+# date: 20251128
+
+import base64
+
+import streamlit as st
+
+
+@st.cache_data
+def convert_image_to_base64(image_path):
+    with open(image_path, 'rb') as f:
+        return base64.b64encode(f.read()).decode()