Set RGBA as the default format of input images.

app.py

@@ -318,7 +318,7 @@ descriptions = ('Upload a picture, our model will extract a highly accurate segm
 tab_image = gr.Interface(
     fn=predict,
     inputs=[
-        gr.Image(label='Upload an image'),
+        gr.Image(label='Upload an image', image_mode='RGBA'),  # Keep alpha channel
         gr.Textbox(lines=1, placeholder="Type the resolution (`WxH`) you want, e.g., `1024x1024`.", label="Resolution"),
         gr.Radio(list(usage_to_weights_file.keys()), value='General', label="Weights", info="Choose the weights you want.")
     ],

app_local.py

@@ -313,7 +313,7 @@ descriptions = ('Upload a picture, our model will extract a highly accurate segm
 tab_image = gr.Interface(
     fn=predict,
     inputs=[
-        gr.Image(label='Upload an image'),
+        gr.Image(label='Upload an image', image_mode='RGBA'),  # Keep alpha channel
         gr.Textbox(lines=1, placeholder="Type the resolution (`WxH`) you want, e.g., `1024x1024`.", label="Resolution"),
         gr.Radio(list(usage_to_weights_file.keys()), value='General', label="Weights", info="Choose the weights you want.")
     ],