Update app.py

app.py

@@ -7,8 +7,6 @@ from PIL import Image
 
 from rapid_layout import RapidLayout, VisLayout
 
-layout_engine = RapidLayout()
-
 st.markdown(
     "<h1 style='text-align: center;'><a href='https://github.com/RapidAI/RapidLayout' style='text-decoration: none'>Rapid Layout</a></h1>",
     unsafe_allow_html=True,
@@ -66,9 +64,12 @@ model_types = {
         "toc",
     ],
 }
-option = st.selectbox("选择版面分析模型：", model_types.keys())
+select_model = st.selectbox("选择版面分析模型：", model_types.keys())
 st.write("支持检测类型：")
-st.code(model_types[option], language="python")
+st.code(model_types[select_model], language="python")
+
+with st.spinner(f"Downloading {select_model} model..."):
+    layout_engine = RapidLayout(model_type=select_model)
 
 st.write("请上传图像：")
 img_suffix = ["png", "jpg", "jpeg"]