Update app.py

app.py

@@ -46,7 +46,8 @@ if __name__ == "__main__":
     st.title("Sartorius Cell Segmentation")
 
     uploaded_img = st.file_uploader(label="Upload neuronal cell image")
-    st.image(uploaded_img)
+    if uploaded_img is not None:
+        st.image(uploaded_img)
     segment = st.button("Perform segmentation")
     if uploaded_img is not None and segment:
         img = Image.open(uploaded_img)