Tag values are ignored in JPEG XMP construction

[EpicWink]

Tag values (not attributes) are ignored when constructing the XMP from JpegImageFile.getxmp.

My (panorama) image has XMP (APP1):

http://ns.adobe.com/xap/1.0/\x00
<?xpacket begin='\xef\xbb\xbf' id='W5M0MpCehiHzreSzNTczkc9d'?>
<x:xmpmeta xmlns:x='adobe:ns:meta/' x:xmptk='Image::ExifTool 11.88'>
  <rdf:RDF xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
    <rdf:Description rdf:about='' xmlns:GPano='http://ns.google.com/photos/1.0/panorama/'>
      <GPano:CroppedAreaImageHeightPixels>7985</GPano:CroppedAreaImageHeightPixels>
      <GPano:CroppedAreaImageWidthPixels>22944</GPano:CroppedAreaImageWidthPixels>
      <GPano:CroppedAreaLeftPixels>0</GPano:CroppedAreaLeftPixels>
      <GPano:CroppedAreaTopPixels>3487</GPano:CroppedAreaTopPixels>
      <GPano:FullPanoHeightPixels>11472</GPano:FullPanoHeightPixels>
      <GPano:FullPanoWidthPixels>22944</GPano:FullPanoWidthPixels>
      <GPano:ProjectionType>equirectangular</GPano:ProjectionType>
      <GPano:SourcePhotosCount>24</GPano:SourcePhotosCount>
      <GPano:StitchingSoftware>Hugin</GPano:StitchingSoftware>
      <GPano:UsePanoramaViewer>True</GPano:UsePanoramaViewer>
    </rdf:Description>
  </rdf:RDF>
</x:xmpmeta>
<?xpacket end='w'?>

Which currently Pillow resolves to:

{
    'RDF': {},
    'Description': {'about': ''},
    'CroppedAreaImageHeightPixels': {},
    'CroppedAreaImageWidthPixels': {},
    'CroppedAreaLeftPixels': {},
    'CroppedAreaTopPixels': {},
    'FullPanoHeightPixels': {},
    'FullPanoWidthPixels': {},
    'ProjectionType': {},
    'SourcePhotosCount': {},
    'StitchingSoftware': {},
    'UsePanoramaViewer': {},
}

You can replicate the above result with:

import types
from PIL.JpegImagePlugin import JpegImageFile

content = b"""<paste XML from above>"""
im = types.SimpleNamespace(_xmp={}, applist=[("APP1", content)])
print(JpegImageFile.getxmp(im))

My optimistic expectation would be:

{
    "xmpmeta": {
        "xmptk": "Image::ExifTool 11.88",
        "RDF": {
            "Description": {
                "about": "",
                "CroppedAreaImageHeightPixels": "7985",
                "CroppedAreaImageWidthPixels": "22944",
                "CroppedAreaLeftPixels": "0",
                "CroppedAreaTopPixels": "3487",
                "FullPanoHeightPixels": "11472",
                "FullPanoWidthPixels": "22944",
                "ProjectionType": "equirectangular",
                "SourcePhotosCount": "24",
                "StitchingSoftware": "Hugin",
                "UsePanoramaViewer": "True",
            },
        },
    },
}

My environment:
OS: Ubuntu 20.04.2
Python: 3.8.5
Pillow: 8.2.0

[radarhere]

I've created PR #5455 - it should change the output to match your expectation.

[radarhere]

Hi. Pillow 8.3.0 has now been released with updated format.

However, be aware that we've added a new requirement - as a security feature, you will have to install defusedxml to get it to work. See #5565 for more information