Bug 431964

Summary:	Face tags are not read correctly on certain images with more than one Microsoft People Tags XMP metadata
Product:	[Applications] digikam	Reporter:	José Oliver-Didier <jose_oliver>
Component:	Metadata-Xmp	Assignee:	Digikam Developers <digikam-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	caulier.gilles, metzpinguin
Priority:	NOR
Version:	7.1.0
Target Milestone:	---
Platform:	Microsoft Windows
OS:	Microsoft Windows
Latest Commit:	https://invent.kde.org/graphics/digikam/commit/a3a4de03fc70e451b7f02f8318ae7090b6a6fcb8	Version Fixed In:	7.2.0
Sentry Crash Report:
Attachments:	Sample images exhibiting issue.

Description José Oliver-Didier 2021-01-23 00:35:23 UTC

Created attachment 135076 [details]
Sample images exhibiting issue.

SUMMARY
Digikam is unable to read face tags correctly on certain images with more than one Microsoft People Tags XMP in which some of the tags do not contain face regions (MPReg:Rectangle) and/or People's names (MPReg:PersonDisplayName). Sample images included as attachment.

STEPS TO REPRODUCE
1. Obtain a photo with multiple people tags in which only one has face regions added (Refer to XMP snipplet included below).
2. Add photo to Digikam catalog 
3. View photo in Digikam.

OBSERVED RESULT
- MS People tags are not read and displayed by Digikam.

EXPECTED RESULT
- MS People tags should be read and displayed by Digikam.

SOFTWARE/OS VERSIONS
Windows: 10

ADDITIONAL INFORMATION
- It seems like an issue with certain images containing more that one People Tag in which some do not contain face coordinates (MPReg:Rectangle) and/or People's names (MPReg:PersonDisplayName). My guess is that the XMP is not being read properly.

The following XMP Snipplet obtained using Exiftool from test2.jpg. None of the 3 people tags are displayed in Digikam, note that only one has face regions( MPReg:Rectangle):

 <rdf:Description rdf:about='uuid:faf5bdd5-ba3d-11da-ad31-d33d75182f1b'
  xmlns:MP='http://ns.microsoft.com/photo/1.2/'
  xmlns:MPRI='http://ns.microsoft.com/photo/1.2/t/RegionInfo#'
  xmlns:MPReg='http://ns.microsoft.com/photo/1.2/t/Region#'>
  <MP:RegionInfo rdf:parseType='Resource'>
   <MPRI:Regions>
    <rdf:Bag>
     <rdf:li rdf:parseType='Resource'>
      <MPReg:Rectangle>0.757813, 0.237776, 0.046094, 0.055609</MPReg:Rectangle>
     </rdf:li>
     <rdf:li rdf:parseType='Resource'>
      <MPReg:PersonDisplayName>Joseph Stallin</MPReg:PersonDisplayName>
     </rdf:li>
     <rdf:li rdf:parseType='Resource'>
      <MPReg:PersonDisplayName>Winston Churchill</MPReg:PersonDisplayName>
      <MPReg:Rectangle>0.211957, 0.265014, 0.051242, 0.062917</MPReg:Rectangle>
     </rdf:li>
     <rdf:li rdf:parseType='Resource'>
      <MPReg:PersonDisplayName>Harry Truman</MPReg:PersonDisplayName>
     </rdf:li>
    </rdf:Bag>
   </MPRI:Regions>
  </MP:RegionInfo>
 </rdf:Description>

- The MS People Tag schema allows for Region info items to contain a Rectangle region without an associated person's name as well as PersonDisplayName tags with no regions associated to it.
- Reference: Microsoft People Tags Schema Refence: https://docs.microsoft.com/en-us/windows/win32/wic/-wic-people-tagging#schema-reference

Comment 1 Maik Qualmann 2021-01-23 11:58:00 UTC

Git commit a3a4de03fc70e451b7f02f8318ae7090b6a6fcb8 by Maik Qualmann.
Committed on 23/01/2021 at 11:57.
Pushed by mqualmann into branch 'master'.

fix reading Microsoft People Tags XMP metadata
FIXED-IN: 7.2.0

M  +2    -1    NEWS
M  +2    -3    core/libs/metadataengine/dmetadata/dmetadata_faces.cpp

https://invent.kde.org/graphics/digikam/commit/a3a4de03fc70e451b7f02f8318ae7090b6a6fcb8

Comment 2 Maik Qualmann 2021-01-23 12:05:20 UTC

The person "Winston Churchill" is now assigned the correct facial region and tag. Likewise, the person "Joseph Stallin" has a face region but no name. People without valid face regions are not added as a tag. Same behavior as in Picasa. If a digiKam version with this patch is available, you will have to read the metadata again. It is recommended to temporarily activate the option to clean up the database in the digikam metata settings.

Maik

Comment 3 José Oliver-Didier 2021-01-24 20:20:42 UTC

Thanks Maik for your prompt response and fix!

This would still ignore tags with names without associated face regions, unless  if they are included within the digikam tag list (people/<name>) then they are recognized as people in digikam. Also, Digikam seems to ignore the IPTC Person shown in image lists. I opened bug 432048 as a related issue.