Changing dates in XMP

Posted on 2009-04-22 04:30:54-07 by billman

I'm new to exiftool and it seems to do exactly what I want it to do: fix dates on images taken with a camera with an improper date set. I'm trying to fix Nikon NEF files and am have a terrible time trying to get everything to work right. I'm using exiftoolGUI (the command line is a bit of challenge for me). It seems to work right on the NEF files, but Adobe Bridge isn't picking up the right dates. Despite was exiftoolGUI seems to be able to do (e.g. copy exif dates to the xmp file), it seems that the dates in the XMP file aren't updated. Any recommendations on how I can fix the dates in the XMP file? (I'd hate to have to recreate them all.) Bill

Direct Responses: 10517 | Write a response

Posted on 2009-04-23 00:58:16-07 by exiftool in response to 10512

Re: Changing dates in XMP

I was hoping that Bogdan was reading this and could tell you if exiftoolgui can do this. - Phil

Direct Responses: 10518 | Write a response

Posted on 2009-04-23 02:47:15-07 by billman in response to 10517

Re: Changing dates in XMP

Phil: there's a modify function "XMP: DateTime copy from EXIF...", but either it doesn't work or I don't know how to use it. I don't think it operates on *.xmp files produced by Bridge. I think I have the command line figured out. I've learned I need to practice on a set of copies, first, though! :-) One interesting thing: -xmp:AllDates+= doesn't change xmp:DateTimeDigitized. I did AllDates first then had to go back and do DateTimeDigitized. exiftoolGui is good for inspection! Thanks for your response. Bill

Direct Responses: 10525 | Write a response

Posted on 2009-04-23 17:04:25-07 by bogdan in response to 10518

Re: Changing dates in XMP

Hi Bill,

Sorry I'm a bit late on this.
In short: I'm not "very" familiar with Adobe Bridge. When I've implemented "XMP: DateTime copy from EXIF" (into GUI), it was after trying out Adobe Lightroom -which had some DateTime bugs at that time. This GUI option copies three DateTime tags into XMP:
EXIF:DateTimeOriginal into XMP:DateTimeOriginal
EXIF:CreateDate into XMP:DateTimeDigitized
EXIF:ModifyDate into XMP:ModifyDate
-at that time, only these three tags existed (and as mentioned, caused troubles inside Lightroom).

As XMP can contain almost anything, there might be more than three DateTime tags (serving different purposes). And going further, new DateTime tags might be added in future. Speaking for me (off topic): only EXIF DateTime values matter.
Now, as far I know (after trying out Adobe Photoshop), you should be able to modify various XMP DateTime values using Adobe software (Bridge?). Have you tried?
Anyway, I'm quite sure, using Exiftoot "pure", you can edit any existing XMP DateTime tag.

Could you name the XMP tag you wish to modify (and from which EXIF tag you wish value to be copied)?

Greetings,
Bogdan

Direct Responses: 10526 | Write a response

Posted on 2009-04-23 17:35:16-07 by billman in response to 10525

Re: Changing dates in XMP

Thanks for the response, Bogdan. Your description of what the "XMP: DateTime copy from EXIF" function does doesn't work for me - though that is exactly what I wanted it to do. (Assumption check: each of my *.nef images has an *.xmp sidecar file and I *assumed* that this function would copy the exif dates from the *.nef file to the corresponding *.xmp file. This isn't what happend and is perhaps a bad assumption.) I did manage to successfully change the datetime values in the *.xmp files using the exiftool command line (and two passes, AllDates and DateTimeDigitized, as I described above) and noticed that the order of the tags in the *.xmp file changed significantly (as viewed in exiftoolGUI). This, to me, supports your bugginess claim of adobe's handling of xmp files. (The xmp tags I wanted to change were exactly those that you mentioned.) Thanks again, and thanks for Phil, for your responses. ExiftoolGUI and exiftool are nice tools! Bill

Direct Responses: 10528 | Write a response

Posted on 2009-04-23 19:30:28-07 by bogdan in response to 10526

Re: Changing dates in XMP

Hi Bill,

Yes, copying DateTime values from EXIF to XMP executes only within selected images! And, if you execute this command inside GUI, you can notice, XMP DateTime tags have been added into NEF image.

Now, some hints (and ideas maybe):
As said, when copying DateTimes from EXIF to XMP, those values are written into XMP (inside NEF files). You can decide to either delete XMP (DateTime) data from NEF, or you can import various XMP data from sidecar files into NEF (to have all inside single file).
Anyway, once (done by GUI) DateTimes are inside XMP of each NEF file, you can use "Import XMP metadata..." menu, to copy existing XMP data from NEF files into XMP sidecar files (to update DateTime tags). After this is done, you can remove XMP metadata from NEF files, though.
If worth something: I keep all XMP metadata inside raw files (Canon in this case) and everything works fine: all photo editors and even Canon software recognises them as such -and I don't need to bother with those sidecars.

Have a nice day,
Bogdan

Direct Responses: 10539 | Write a response

Posted on 2009-04-24 15:45:42-07 by billman in response to 10528

Re: Changing dates in XMP

Thanks, Bogdan - you've given me something to think about and consider. I'd guess I just accepted that .xmp sidecar files were needed because Bridge created them and there was no other option. Based on what you've told me, that evidentally is not the case. Bill

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