@cameronneylon I don’t think there is an “accepted standard”. Probably the most generic you could use is Dublin Core.
There is a XMP dc namespace https://www.exiftool.org/TagNames/XMP.html#dc which could be used to add metadata to the image directly.
Something that can survive passage through a presentation an added bonus!
I wouldn’t trust any processing steps to preserve image metadata though. I think most softwares just strip an image clean before using it.