Update app.py

app.py

@@ -116,7 +116,9 @@ def load_img(filename, norm=True):
 
 
 def inference(image, upscale, large_input_flag, color_fix):
-	upscale = int(upscale) # convert type to int
+    if upscale is None or not isinstance(upscale, (int, float)):
+        upscale = 2 
+    upscale = int(upscale)
 	if upscale > 4: 
 		upscale = 4 
 	if 0 < upscale < 3:
@@ -216,7 +218,7 @@ demo = gr.Interface(
     fn=inference,
     inputs=[
         gr.Image(value="real_testdata/004.png", type="pil", label="Input"),
-        gr.Number(minimum=2, maximum=4, label="Upscaling factor (up to 4)"),
+        gr.Number(minimum=2, maximum=4, default=2, label="Upscaling factor (up to 4)"),
 		gr.Checkbox(value=False, label="Memory-efficient inference"),
         gr.Checkbox(value=False, label="Color correction"),
     ],