This question is not answered. Helpful answers available: 2. Correct answers available: 1.


Permlink Replies: 11 - Pages: 1 - Last Post: 28-Oct-2018 11:01 Last Post By: jGromit
jGromit

Posts: 8,621
Registered: 31-Jan-2006
"List metadata" error
Posted: 26-Oct-2018 17:02
 
  Click to reply to this thread Reply
Attachment DSC_2881.JPG (4.5 MB)
Take a look at the metadata in the attached image file. Notice the Windows XP fields, and compare to the xmp fields. The extension tells me this:
Windows XP Comment=XP comment
Windows XP Subject=XP subject
Windows XP Title=XP title
...
xmp.dc:description[1]=XP title
xmp.dc:title[1]=XP title
But if I tell jAlbum to use only xmp as the comment source, it's actually picking up "XP comment" as the comment for that image. Where is it getting that from?
jGromit

Posts: 8,621
Registered: 31-Jan-2006
Re: "List metadata" error
Posted: 26-Oct-2018 17:41   in response to: jGromit in response to: jGromit
 
  Click to reply to this thread Reply
A confirmation that the extension is incorrect - in one of my skins, I asked it to display the contents of xmp.dc:description[1] as a "custom" metadata field. It coughed up "XP comment," not "XP title" - the extension shows "XP title" in that xmp field.
RobM

Posts: 3,348
Registered: 4-Aug-2006
Re: "List metadata" error
Posted: 26-Oct-2018 18:47   in response to: jGromit in response to: jGromit
 
  Click to reply to this thread Reply
I have to admit to glazing over when I see Windows XP metadata, is this post relevant?
jGromit

Posts: 8,621
Registered: 31-Jan-2006
Re: "List metadata" error
Posted: 26-Oct-2018 18:54   in response to: RobM in response to: RobM
 
  Click to reply to this thread Reply
This is really just about the xmp metadata. The "List metadata" extension is telling me one thing, but the actual xmp metadata are different.
davidekholm

Posts: 3,853
Registered: 18-Oct-2002
Re: "List metadata" error
Posted: 27-Oct-2018 16:12   in response to: jGromit in response to: jGromit
 
  Click to reply to this thread Reply
jAlbum 17 maps the XP description to its "comment" variable and the "XP title" to its title variable. I think that's the correct behavior. Furthermore, when you edit the title or comment within jAlbum, then the corresponding xmp fields are updated correctly.

When Windows once wrote metadata to that file, it incorrectly wrote the XP title to both the dc:description and dc:title xmp fields. jAlbum 17 detects corrects this but doesn't re-write the file until you edit the comment within jAlbum. For this reason, please rely on the high level "comment" and "title" fields which are corrected instead of relying on the low-level fields that metadata-extractor picks up.
jGromit

Posts: 8,621
Registered: 31-Jan-2006
Re: "List metadata" error
Posted: 27-Oct-2018 16:20   in response to: davidekholm in response to: davidekholm
 
  Click to reply to this thread Reply
davidekholm wrote:
jAlbum 17 detects corrects this but doesn't re-write the file until you edit the comment within jAlbum.

I can at least confirm that behavior. But I think that when I ask jAlbum to display the metadata present for an image, it should tell me the truth. The xmp field has clearly been corrected - when I do a meta.get(), I'm given the new, corrected value. The extension should display the same thing, not something else.
jGromit

Posts: 8,621
Registered: 31-Jan-2006
Re: "List metadata" error
Posted: 27-Oct-2018 16:31   in response to: jGromit in response to: jGromit
 
  Click to reply to this thread Reply
I should rephrase that. Since the file hasn't actually been rewritten, the core is lying about what's physically in it. The "list metadata" extension should tell the same lie. ;)
davidekholm

Posts: 3,853
Registered: 18-Oct-2002
Re: "List metadata" error
Posted: 27-Oct-2018 16:40   in response to: jGromit in response to: jGromit
 
  Click to reply to this thread Reply
jGromit wrote:
I should rephrase that. Since the file hasn't actually been rewritten, the core is lying about what's physically in it. The "list metadata" extension should tell the same lie. ;)

I can rewrite the xmp data upon import but want to get it confirmed by our community that this way of importing is solid enough before doing so. As soon as you edit either the title or comment from within jAlbum, then the updated/corrected xmp data is written to file too.
jGromit

Posts: 8,621
Registered: 31-Jan-2006
Re: "List metadata" error
Posted: 27-Oct-2018 16:59   in response to: davidekholm in response to: davidekholm
 
  Click to reply to this thread Reply
I think the basic premise is correct:

XP Title > jAlbum title and xmp.dc:title[1]

XP Comment > jAlbum comment and xmp.dc:description[1] (correcting the Windows "write the title to both xmp fields" error in the process)

The other commonly-used Windows XP field that should probably be grabbed is Windows XP Subject. It doesn't correspond to any normal jAlbum variable, but planting it in xmp.dc:subject[1] might not be a bad idea. Some future skin might want to make use of it.

ETA: But only if xmp.dc:subject[1] is currently empty, of course.
davidekholm

Posts: 3,853
Registered: 18-Oct-2002
Re: "List metadata" error
Posted: 27-Oct-2018 22:36   in response to: jGromit in response to: jGromit
 
  Click to reply to this thread Reply
jGromit wrote:
I think the basic premise is correct:

XP Title > jAlbum title and xmp.dc:title[1]

XP Comment > jAlbum comment and xmp.dc:description[1] (correcting the Windows "write the title to both xmp fields" error in the process)

The other commonly-used Windows XP field that should probably be grabbed is Windows XP Subject. It doesn't correspond to any normal jAlbum variable, but planting it in xmp.dc:subject[1] might not be a bad idea. Some future skin might want to make use of it.

ETA: But only if xmp.dc:subject[1] is currently empty, of course.


I could do so, and also add a "subject" variable.
jGromit

Posts: 8,621
Registered: 31-Jan-2006
Re: "List metadata" error
Posted: 27-Oct-2018 23:44   in response to: davidekholm in response to: davidekholm
 
  Click to reply to this thread Reply
davidekholm wrote:
I could do so, and also add a "subject" variable.

Despite what I said earlier, I wouldn't try to grab the WinXP Subject. It's just too messy. Just grab xmp.dc:subject[1] and create a jAlbum subject variable with it.

The "subject" metadata turns out to be a friggin' minefield. Windows, for example, grabs that xmp subject and plants it in its own "tags" field. Meanwhile, it has its own "subject" field, which is different. It just gets worse and worse. This is a chance to take at least a small step to standardization on xmp.

One of my longstanding suggestions is to force the issue. Retrieve EXIF fields only for camera-provided data, like exposure, aperture, and so on, and maybe GPS (which may or may not be coming from the camera). For everything else, use xmp only. Ditch the IPTC, ditch the WinXP fields, etc. Just flat-out ignore them for the purpose of populating the jAlbum title and comment fields. (Someone who's really determined to use them can still use meta.get() to retrieve other stuff.)

Maybe some of us could work up some instructions about how to use something like ExifTool to batch-process existing images and copy selected fields from other sources and write them out to xmp.

A sledgehammer, but in the long run you'd be doing everyone a favor, I think.

Edited by: jGromit on 27-Oct-2018 18:05. Sorry for all the edits, but the more I tinker with these metadata, the worse it gets.
jGromit

Posts: 8,621
Registered: 31-Jan-2006
Re: "List metadata" error
Posted: 28-Oct-2018 11:01   in response to: jGromit in response to: jGromit
 
  Click to reply to this thread Reply
This all brings up a very old problem that I think it's time to address:

https://jalbum.net/forum/thread.jspa?threadID=54567
Legend
Forum admins
Helpful Answer
Correct Answer

Point your RSS reader here for a feed of the latest messages in all forums