In the child theme's function.php I'd extend the media upload form with two fields. These fields contain additional information for every image. And can be inserted when the image will be uploaded.
Now the way back & my problem:
I want to get the values of these extra fields when I use the common 'Add media file'-Button in the backend editor, so like it works with the caption field.
My questtion: Is that possible with coding within the function.php, and how ?