[Python] How to change and load a png file without refreshing the app?

I have a Shiny for Python app which displays an image. Whenever I regenerate the image from within the app, the entire app reloads, losing the input settings (the slider value resets). Is there a way to refresh the image itself without reloading the app, or is this impossible? I'm using the png library to generate the image.

App code:

from shiny import reactive, render, ui
from shiny.express import input, ui

import imagechanger

with ui.card():
ui.input_action_button("generate", "Generate")
ui.input_slider("slider", "slider", value=1, min=1, max=100)
@render.image
def image():
img = {"src": "image.png"}
return img

@reactive.effect
@reactive.event(input.generate)
def _():
imagechanger.generate_png()
pass


Image generation code:

import png
import random

width = 100
height = 100

img = []
for y in range(height):
row = []
for x in range(width):
row.append([0, 0, 0])
img.append(row)

def generate_png():
for i in range(10):
x = random.randint(1, width-1)
y = random.randint(1, height-1)
img[y][x] = [255, 255, 255]

output = []
for y in range(height):
row = ()
for x in img[y]:
row += tuple(x)
output.append(row)

with open('image.png', 'wb') as f:
w = png.Writer(width, height, greyscale=False)
w.write(f, output)

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