Metadata injection fails silently with non-standard groups present

[eleigh]

I am working with a JPEG file that contains non-standard metadata groups (XMP-mbn and XMP-iX). An example is this public domain image from the Rijksmuseum:
https://lh3.ggpht.com/FkkMpQsDIyGGyfUGafaEKVcrXJXFDMfzDBuIU41XIg8nWGGEQwmHa1ouAL2Zhyl2yw4mBqwAlmUY1tULVdZoTN2QcA=s0

The following sequence of commands leaves the metadata untouched with no error messages, neither when setting values nor writing to the file:

my $exifTool = new Image::ExifTool;
$exifTool->SetNewValue('*');
($rv, $errStr) = $exifTool->SetNewValue('XMP-xmpRights:*', undef, Replace => 2);

[... various subsequent SetNewValue() calls ...]

$rv = $exifTool->WriteInfo($dest);

It seems the attempt to preserve the XMP-xmpRights group conflicts with having unrecognised XMP- groups? Should this not be handled explicitly, with an error and option to override?

[Phil Harvey]

This works for me on the command line, so I'm not sure why it isn't working for you:

Code Select Expand

> exiftool a.jpg "-xmp<=a.xmp"
    1 image files updated
> exiftool a.jpg -xmp:all -G1
[XMP-x]         XMP Toolkit                     : Image::ExifTool 12.01
[XMP-xx]        Testtag                         : this is a test
[XMP-xmpRights] Marked                          : True
[XMP-xmpRights] Usage Terms                     : All rights reserved no usage without express agreement in advance
> exiftool a.jpg -all= --xmp-xmprights:all
    1 image files updated
> exiftool a.jpg -xmp:all -G1
[XMP-x]         XMP Toolkit                     : Image::ExifTool 12.01
[XMP-xmpRights] Marked                          : True
[XMP-xmpRights] Usage Terms                     : All rights reserved no usage without express agreement in advance
> cat a.xmp
<x:xmpmeta xmlns:x='adobe:ns:meta/' x:xmptk='Image::ExifTool 12.01'>
<rdf:RDF xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'>

<rdf:Description rdf:about=''
  xmlns:xx='http://test.org/xx/1.0/xmlns/'>
  <xx:testtag>this is a test</xx:testtag>
</rdf:Description>

<rdf:Description rdf:about=''
  xmlns:xmpRights='http://ns.adobe.com/xap/1.0/rights/'>
  <xmpRights:Marked>True</xmpRights:Marked>
  <xmpRights:UsageTerms>
   <rdf:Alt>
    <rdf:li xml:lang='x-default'>All rights reserved no usage without express agreement in advance</rdf:li>
   </rdf:Alt>
  </xmpRights:UsageTerms>
</rdf:Description>
</rdf:RDF>
</x:xmpmeta>

- Phil

[eleigh]

I just tried this on the command line using Exiftool v12.01 on the example jpeg file linked above:

c:\bin\exiftool\exiftool input.jpg -xmp:all

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XMP Toolkit                     : XMP toolkit 2.9-9, framework 1.6
Metadata Date                   : 2010:04:02 10:19:32Z
Tag                             : #MB%:{F813C3B4-5119-47D4-B7A2-71DAC806E359}S-DAM-1:%MB#
Changes                         : tag,2010-04-02T10:19:32Z,1,c

c:\bin\exiftool\exiftool input.jpg "-all= --xmprights:all"

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Warning: [Minor] IPTC:ServiceIdentifier exceeds length limit (truncated) - input.jpg
    1 image files updated

c:\bin\exiftool\exiftool input.jpg -xmp:all

Code Select Expand

XMP Toolkit                     : XMP toolkit 2.9-9, framework 1.6
Metadata Date                   : 2010:04:02 10:19:32Z
Tag                             : #MB%:{F813C3B4-5119-47D4-B7A2-71DAC806E359}S-DAM-1:%MB#
Changes                         : tag,2010-04-02T10:19:32Z,1,c

The XMP tags have not been removed. If I run it without the --xmprights:all then all metadata is removed as expected.

[StarGeek]

Just a couple of notes

c:\bin\exiftool\exiftool input.jpg "-all= --xmprights:all"

The quotes are incorrect on this command. This will attempt to set every tag to a value of " --xmprights:all" (leading space included).  Which is why you get the IPTC:ServiceIdentifier exceeds length limit warning.  It's writing to IPTC (and EXIF) tags and not clearing any data.  The command you are trying to use is
exiftool input.jpg -all= --xmprights:all

But that also runs into the problem that the group name is incorrect.  I believe what you want to use is XMP-xmpRights,
exiftool input.jpg -all= --XMP-xmpRights:all

Finally, that example file gives a Can't handle XMP attribute 'rdf:ID' warning, which is why it won't update the XMP.  Adding the -m (ignoreMinorErrors) option will force an update.

[eleigh]

Thanks @StarGeek for pointing out my typo and explaining the correction, which makes sense.

Going to back to my Perl project, what I hadn't expected is for WriteInfo to fail with a warning (rather than an error), so I hadn't checked the warning message.

I think it would be more consistent with conventions if:

Minor error/warning = Error [stopping execution]
minor error/warning = Warning [not stopping execution]

In that case Can't handle XMP attribute 'rdf:ID' would be upgraded to an error. The flag IgnoreMinorErrors would then be more accurate: i.e. ignore minor (ignorable) rather than fatal errors.

[Phil Harvey]

But if you were writing other types of metadata (eg. EXIF, IPTC) then they would have been written fine.  Upgrading the XMP warning to an error would break that.

- Phil