title: Saving an Image stored in BytesIO in pillow
body: <p>I have an image stored as BytesIO of Pillow and I need to save it to a file with some header information (containing textual attributes) that I need to add specific to my problem. I need the bytes to be represented according to some  image compression format. Would that be possible? If yes, how it can be done?
  I also need to store more than one image in the file. </p>