Face region metadata propagation : what to expect ?

[tokumeino]

Hi, let's consider the following use case :

• I edit a RAW file in Capture One Pro, with rotations and crops
• I export the croped/rotated JPEG on a NAS
• The NAS automatically recognize faces and adds xmp metadata to store face regions
• I want to use iMatch to backprop metadata from the JPEG to the RAW file's xmp

Is there a chance face regions will be OK provided the original has been croped and rotated ?

[Mario]

This depends on what your NAS does and how it records the face data.
And if you have rotated and cropped and push the region data into another image, it will probably no longer match. This is nothing that is really covered by the XMP standard or regions.

[tokumeino]

This depends on what your NAS does and how it records the face data.
And if you have rotated and cropped and push the region data into another image, it will probably no longer match. This is nothing that is really covered by the XMP standard or regions.

I've actually not tried yet, just thinking about a workflow. But Synology (the brand of my NAS) stated that they store faces as XMP tags (face regions). The second point is the answer I need. What I ask would require no-so-easy calculations, and the information might be unavailable anyway (does C1P store in exported  JPEG metadata how it croped and rotated a picture before exporting ?).

But at least, backprop of people would work, let the accurate region apart, right ?

[Mario]

does C1P store in exported  JPEG metadata how it croped and rotated a picture before exporting ?

Since there is no standard for this, I pretty much doubt it.
There is also a very little use case for this and combining cropping and rotating in different files with face regions and then trying to move these back and forth may be not easy to do.

[Carlo Didier]

I think the best would be to re-trigger face recognition on the cropped/rotated image. Maybe you could trigger that automatically for new/modified images?
Although I also have a Synology NAS, I never used that functionality.

[tokumeino]

Since I edit RAW files on my latpop and the JPEGs are exported the NAS, for some reason, I didn't think about letting the NAS recognize the faces on my original RAW files, despite Synology Moments seems to support RAW : https://nascompares.com/answer/synology-moments-supported-photo-video-file-formats-raw-jpeg-etc/

But recently, I've changed my setup and stored all  the RAW files on the NAS. So thanks, I'll indeed try to let the Syno recognize faces in the RAW files as well, hoping that it will adequately update the XMP sidecars.

One precision : it is OK to store originals on a NAS and work on them even by Wifi, as long as you use the "Always Offline" feature of Windows. My library believes that the files are on a network drive, but Windows manages a local and fast cache for my RAW fles of the last 2 years.

[Carlo Didier]

One precision : it is OK to store originals on a NAS and work on them even by Wifi, as long as you use the "Always Offline" feature of Windows. My library believes that the files are on a network drive, but Windows manages a local and fast cache for my RAW fles of the last 2 years.

Hmm, how many files do you sync that way? I found that my nearly 100000 files would create serious problems to sync correctly and quickly. It was just too slow and unstable.

[tokumeino]

In one year, I keep like 3,000 pictures max, so I sync less than 8.000 pictures including those I didn't cull yet. That's 16,000 files including XMP. So far, so good, but I'm not doing that since a long time. Actually, only XMP files do change so they sync quite quickly. I let the library and cache/previews locally on the laptop.