Uploading, saving, modifying and displaying an Image

Hi! I want to make an app with dash in which the user uploads an image, the application saves it in a predefined local folder, modifies this image and finally shows the original image and the modified one.

I have no problem loading the image, but I don’t know how to store it so I can modify it later.

Could someone guide me on how to do it? Any comments/experience would be greatly helpful. Thank you!