fix mismatch in remove, use default remove

app.py

@@ -8,11 +8,11 @@ logging.basicConfig(level=logging.INFO)
 
 def remove_background(input_image, bg_color, model_name, alpha_matting, post_process_mask, only_mask):
     try:
-        # Set up the session with the chosen model
+        # Set up the session with the chosen model, or None if no model is selected
         session = new_session(model_name) if model_name else None
         
         # Prepare additional options
-        remove_options = {
+        remove_kwargs = {
             "session": session,
             "bgcolor": bg_color if bg_color else None,
             "alpha_matting": alpha_matting,
@@ -20,8 +20,12 @@ def remove_background(input_image, bg_color, model_name, alpha_matting, post_pro
             "only_mask": only_mask
         }
         
-        # Remove the background
-        output_image = remove(input_image, **{k: v for k, v in remove_options.items() if v is not None})
+        # Use the remove function
+        if session:
+            output_image = remove(input_image, **{k: v for k, v in remove_kwargs.items() if v is not None})
+        else:
+            output_image = remove(input_image)  # Use the default remove function
+
         logging.info("Background removed")
 
         # Convert to RGB mode if necessary
@@ -46,7 +50,7 @@ iface = gr.Interface(
     inputs=[
         gr.Image(type="pil"),
         gr.ColorPicker(label="Background Color", value=None), # Background color picker
-        gr.Dropdown(choices=["u2net", "isnet-general-use", "unet"], label="Model Selection", value="u2net"),
+        gr.Dropdown(choices=["", "u2net", "isnet-general-use", "unet"], label="Model Selection", value=""),
         gr.Checkbox(label="Enable Alpha Matting", value=False),
         gr.Checkbox(label="Post-Process Mask", value=False),
         gr.Checkbox(label="Only Return Mask", value=False)