BACKGROUND Uploading lots of stuff to Google Photos. Because of how Google sorts photo albums, if an album contains a photo with a recently modified file timestamp it will show up first in the list of albums. I therefore am careful about ensuring all photos in a digikam album have EXIF original, create and file timestamps set to that of the original photo. This ensures that the date ranges of albums are correct, which ensures that my albums are sorted correctly. PROBLEM Once I have updated all the time stamps in a digikam album, I export it to Google Photos. Only, Digikam seems to update the file modified timestamp in the export process. This means all my photos end up with file modified timestamps set to the time of the upload. The export doesn't modify my photos (?), so why does it modify the timestamps? INFO Currently on Linux Mint 18.1 with Digikam running on Cinnamon desktop. Not all digikams GUI buttons display correctly but functionally seem to work. My photos and digikam files are stored on a btrfs volume, mounted with relatime option. Mentioning this but it should not be relevant, my bug report is really that the Export process shouldn't update the file modified timestamp of photos.
This bug could already closed. Did you have enabled metadata sidecar files? Maik
Well I found the Metadata / Behaviour / Reading and Writing Metadata settings category: I'm not sure what 'Read from sidecar files' and 'Write to sidecar files' settings do, but turning off the "Update file timestamps when files are modified" seems to do the trick. What are sidecar files?
Look XMP sidecar here : https://en.wikipedia.org/wiki/Sidecar_file Gilles Caulier
There is an option in Settings / Configure digikam / Metadata / Behaviour / Reading and Writing Metadata / Update file timestamps when files are modified which when turned OFF, export to Google Photos does not change the file timestamps. However, even when this option is ON, exporting files to Google Photos should NOT update the file timestamps. Ie. the bug is file timestamps are updated even when the only action taken is to export files.
Thanh, This file still valid with your GSoC 2018 devel branch ? Best Gilles Caulier
Gilles, I saw the same problem when I tried to export to Google Photo. I unintentionally discovered that timestamp is modified because at the final phase of exporting, the image id is written to the metadata. I think that if the XMP is load and then save again, timestamp will be modified to that moment. Could you confirm my theory? Best Thanh.
Thanh, This can be the problem yes. But we have an option in Setup/Metadata/Behavior to update file time-stamp when files are modified. Changing this option can have also an effect for this file. Gilles
Tested. If right option described in comment 7 is turned on, file time stamp is not changed as expected. I close this file now.