I want to automate thumbnail deletion on several files (40K to 50K) and was wondering if I would have to create a script that besides executing exiftool to delete the thumbnail also do some kind of checking for corruption so was wondering what are the chances of a file corrupting by only deleting its thumbnail. Since you are experts can you please share your input.
Does exiftool checks whether the output file is corrupted and aborts the creation/modification of the file? Asking because I'm thinking on executing exiftool without creating any backup (I already have backups of my data) as I would like to avoid ending up with 100K files.
I would like to delete the embedded thumbnails (if there is any) because I want to compare the files by checksum and if one has a thumbnail and the other doesn't then they wont match. These are files that come from various sources: my phone / camera, Internet, backups from third party apps, shared by other people, etc.
I've deleted thumbs from images I've downloaded from the web for years with exiftool and there has never been a problem. As per FAQ #13 (https://exiftool.org/faq.html#Q13), exiftool does not touch the image data when editing. It directly copies it. The thumbnail is in a separate part of the file from the actual image data.
Personally, I don't remove the thumbs from images I've taken with my camera. And while I doubt there would be a problem, I probably wouldn't remove them from RAW file types. I freely edit the metadata in my RAW files with exiftool, but never remove anything.
Thank you! I've done the process in a small batch and it was pretty fast, I even found some files with errors and was able to fix them with exiftool.