added progress bar

app.py

@@ -210,6 +210,7 @@ st.markdown("This app puts color into your black and white pictures")
 st_title_message = st.empty()
 st_progress_bar = st.empty()
 st_file_uploader = st.empty()
+st_submit_button = st.empty()
 st_input_img = st.empty()
 st_output_img = st.empty()
 st_download_button = st.empty()
@@ -244,7 +245,7 @@ if colorizer is not None:
         uploaded_files = st_file_uploader.file_uploader("Upload a black and white photo", 
                                                 type=['png', 'jpg', 'jpeg'],
                                                 accept_multiple_files=True)
-        submitted = st.form_submit_button("UPLOAD!")
+        submitted = st_submit_button.form_submit_button("UPLOAD!")
 
     if submitted and uploaded_files is not None:
         if len(uploaded_files) == 1: