png format

app.py

@@ -46,7 +46,7 @@ if __name__ == "__main__":
             examples = gr.Examples(examples=examples_data, inputs=[input_img])
             run_btn = gr.Button(variant="primary")
         with gr.Row():
-            output_mask = gr.Image(label="mask")
-            output_img = gr.Image(label="result", image_mode="RGBA")
+            output_mask = gr.Image(label="mask", format="png")
+            output_img = gr.Image(label="result", image_mode="RGBA", format="png")
         run_btn.click(rmbg_fn, [input_img], [output_mask, output_img])
     app.launch()