Image.change event is triggered twice since 3.31.0

[nqdeng]

Describe the bug

Before 3.31.0, Image.change event is only triggered once by a function update, But since 3.31.0, the event is triggered twice.

Have you searched existing issues? 🔎

• I have searched and found no existing issues

Reproduction

import gradio as gr

def onchange(image):
    print(image)

block = gr.Blocks().queue()

with block:
    temp = gr.Image(source='upload', type='pil')
    image = gr.Image(source='upload', type='pil')
    temp.change(onchange, inputs=[temp])
    image.upload(lambda x:x, inputs=[image], outputs=[temp])

block.launch(server_name='0.0.0.0', server_port=5000)

After the service is started, you could click the second Image control to upload an image, and will see the following logs:

Running on local URL:  http://0.0.0.0:5000

To create a public link, set `share=True` in `launch()`.
<PIL.Image.Image image mode=RGB size=512x512 at 0x1628DF070>
<PIL.Image.Image image mode=RGB size=512x512 at 0x162B1EF80>

This issue only happens when gradio version >= 3.31.0, 3.30.0 and below are fine to me.

Screenshot

No response

Logs

No response

System Info

gradio>=3.31.0
MacOS 13.3.1
Chrome 113.0.5672.126

Severity

Blocking usage of gradio

[picobyte]

I've come across this issue as well. in my branch of stable-diffusion-webui-wd14-tagger I circumvented every first callback using:

def on_interrogate_image_change(*args):
    # FIXME for some reason an image change is triggered twice.
    # this is a dirty hack to prevent summation/flushing the output.
    print("interrogator: "+args[1])
    It.image_counter += 1
    if It.image_counter & 1 == 0:
        return It.results()
    return on_interrogate_image(*args)


def on_interrogate_image(image: Image, interrogator: str, unload_after: bool):
    if image is None:
        return [None, None, None, 'No image']

    if interrogator not in utils.interrogators:
        return [None, None, None, f"'{interrogator}': invalid interrogator"]

    interrogator: It = utils.interrogators[interrogator]
    return interrogator.interrogate_image(image, unload_after)

[freddyaboulton]

Thanks for filing @nqdeng and for posting the workaround @picobyte . Going to look into this.

[picobyte]

Was the issue resolved? I rewrote my code a bit and now no longer seem to have the issue.

[abidlabs]

This issue is not resolved on main as far as I can tell. Just tested with a very simple demo:

import gradio as gr

def test(x):
    print("change called")
    return x

with gr.Blocks() as demo:
    a = gr.Image()
    b = gr.Image()
    
    a.change(test, a, b)
    
demo.launch()

I'm tackling the analogous issue for Video so lmk if I should take this as well @freddyaboulton

[freddyaboulton]

Feel free to take @abidlabs ! I have not started on this yet