>>1484101Since it's a grayscale image, you can just pick the green channel and discard the other two (Channels tab in Photopea/shop).
It's not perfect because the JPEG compression made every channel bleed into each other.
If it were full-color, you would have to undo the transformations that were applied to each channel.
In this case, it would be a matter of scaling down the red channel and scaling up the blue channel.
