Timeline for Where is a pointer to what metadata each photo editing package preserves?
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 29, 2018 at 18:28 | comment | added | Sherwood Botsford | The ID string is irrelevant. The issue is to find a subset of exif and IPTC fields such that at least one is left intact by the top N most used photo editors. | |
| Jan 28, 2018 at 16:21 | comment | added | flolilo | @SherwoodBotsford well - if your program deletes metadata that it cannot see, then your program basically sucks ;-) really, if that is one of your design goals, you have to hope that all programs from the ones you use now to those you use in 20 years take the same fields into account. I wouldn't bet a penny on still having JPEGs in 20 years time, so basically, you will have to make sacrifices. | |
| Jan 28, 2018 at 16:17 | comment | added | flolilo | @SherwoodBotsford No - you just calculate the hash of the original file and write that to all derivatives. the hashis just used as a source for a unique string - it is completely unrelated fo anything else. you could just as well use timestamps or literally anything else that willnot lead to duplicated strings in the near future. theoretically, you can even change the string-source in between - as long as your old SHA-256 hashes don't collide with your new source, for example. | |
| Jan 28, 2018 at 16:16 | comment | added | Sherwood Botsford | Care has to be taken in choosing fields: They have to be ones that are normally not used, but that editing programs don't discard. It can be a string within another field, with the rest of the field ignored. e.g. Copyright blah blah blah -- ID:stringID I want to avoid using as a keyword so that keyword indexing doesn't get filled with strings of random stuff. | |
| Jan 28, 2018 at 16:12 | comment | added | Sherwood Botsford | For the sake of portability and robustness I'd like the string to be identical on all hosts. e.g. if you have multiple people using multiple computers to write to a NAS, the ID should be unique for all files, and identical on all computers. A hash of the preview image is another possibility. | |
| Jan 28, 2018 at 14:44 | history | answered | flolilo | CC BY-SA 3.0 |