Integrity of JPG and DNG files: Any suggestions for managing bitrot?

Hert
Posts: 6250
Joined: 13 Sep 03 7:24

Re: Integrity of JPG and DNG files: Any suggestions for managing bitrot?

Post by Hert » 01 Jul 20 0:31

Psu keeps signatures for every file. Use Verify -> Verify Full will scan through a folder, looking for files that have changed signatures (in contrast to verify quick, which checks for changed file stamp and file size).
This is a User-to-User forum which means that users post questions here for other users.
Feature requests, change suggestions, or bugs can be logged in the ticketing system

babarnc
Posts: 18
Joined: 20 Jun 20 12:13

Re: Integrity of JPG and DNG files: Any suggestions for managing bitrot?

Post by babarnc » 01 Jul 20 18:04

Hi Hert,
Thank you for the tip. Which kind of integrity check does this signature procure?

I mean does it compute a signature for the full file including metadata or only the image data?

If it checks the full file integrity it is just a partial solution for me, but if it checks the image only integrity then I love it.



If you remember a few days ago I moved my entire collection to PSU that is several thousands of images as most people nowadays. And some of my tiff file got corrupted by PSU (bug fixed in last version - thank you for your very fast response to the issue). I would never have noticed that some almost 40 years old photos had been corrupted if not by separately running exiftool to detect this kind of issue (over the years I became quite paranoid with database migations on my photos...)
The script is very time consuming as I strip off all metadata from a copy of the photos and then compute the MD5 checksum and finally I compare it in excel (except for DNG where I rely on adobe functionality). So that is not something I like doing very much.
This example is also proving that file corruption does not only happen from disk failure but also from softwares (be it PSU or adobe ) so it is best to be able to properly check the photos before a backup is done.

thanks

babarnc
Posts: 18
Joined: 20 Jun 20 12:13

Re: Integrity of JPG and DNG files: Any suggestions for managing bitrot?

Post by babarnc » 01 Jul 20 18:24

Ho, I forgot to ask but from what I saw in the PSU block of metadata I suppose this is the case:
Is the signature saved with the file?

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