Maintaining EXIF / IPTC within derivative images

I would like to retain the copyright, rights, IPTC contact information, and our unique reference identifier embedded within the EXIF on each image that is imported using CSVImport. This EXIF information is wiped clean, when any of the derivative images are created by ImageMagick conversion process.

I am not talking about the extraction of EXIF into the omeka db, but rather the actual fullsize, thumbnail, thumbnail_square images that are created and display upon importing the image file.

Any warnings on using exiftool to add back some of the missing EXIF/IPTC information directly within the directories of the derivative images. Is that going to throw off the any file checksums verification?

Using exiftool might work in order to put back the IPTC contact information but not the unique identifier. Is there a way to determine the original filename for the derived images.

Are the Omeka generated file names, some sort of checksum or hash? Is it possible to determine what the original file names were based upon the generated file name?

You can't tell what the original file name was from the random filename.

Omeka stores the original filename in the database, along with a hash checksum of the original file, but there's no hashes of the derivative files; they'd be different already after being resized.