After tinkering some time with Windows 7 and its metadata capabilities, I think its time to publish some of my findings:
- Good: Windows 7 handles XMP metadata better than Vista
- Bad: its still not right…
- Ugly: remains a Grim Reaper – may eat and hide your metadata
Windows 7 writes the XMP block now correctly to image files, with a nice buffer of 2 kBytes for any future editing of metadata items. So, adding a keyword to a 10 MP image file will no longer automatically re-write the entire file (less coffee breaks for you…).
Vista added the buffer after the XMP block already ended (which made it useless).
Microsoft is one of the founders of the Metadata Working Group, which is trying to simplify the use of metadata for certain user groups. MWG is a great initiative, and Windows 7 should really support it all the way.
Rating Your Images
Rating your pictures on a scale from 0 to 5 stars is a nice way to find your greatest shots again. MWG therefore added the rating field to its set of 7 essential metdata items for consumer users.
This rating value is supposed to be stored in XMP (xmp:rating). Windows 7 does this initially right, but also stores it in up to three additional places inside your file’s metadata. Here is were the problem begins – try this:
• add or edit an image rating in Windows Explorer; lets say to 3
• now, edit this rating in different programm (FileMind, ExifTool, LR, etc.); lets say to 5.
• take a look again in Windows 7 Explorer: it still has a rating of 3.
• take a look in Windows Vista Explorer: it shows 5.
Why is this? Windows gets apparently confused what to do with all its own different internal rating values and, under Windows 7, picks the wrong one ( which should be xmp:rating). So, unless you plan to stick solely with Windows Explorer for adding image ratings, it may be a bad idea to trust it at this point.
If, however, you think XMP’s feature to allow “language-qualified” values in fields such as Description and Copyright Notice is a wonderful idea, then you may have another reason to keep your files away from the Windows Explorer.
Try this: take a file that has a description field (the XMP field dc:description) in English and German. You can check the values nicely with some free tools that show language-qualified fields (i.e., ExifTool). All seems fine, right? Try this:
1, Select the image file in the Windows Explorer under Windows 7. It will claim that the file has NO description at all (Windows Explorer calls the field Subject). If you now add a new description, then Windows 7 will only store it in a proprietary field called XPSubject inside the file’s Tiff metadata (not XMP). Your existing dc: description is nowhere to be seen.
2, Now, try the same under Windows Vista. When you select the file, it too, will show you nothing under the Subject field. Unlike in Windows 7 however, if you try to edit it you will get an “unexpected error” message that lets you know that Windows is … confused. At least it wont sneak a new ‘undercover’ description field into the Tiff block of your file.
3, If you are a fan of real confusion, then take the file that was mangled under Windows 7 (under 1,) and now view it under Windows Vista. Surprise – now Vista shows the correct value of the XMP metadata item dc:description in its Subject field…
The above is a excerpt of my observation about how Windows 7 treats file-based metadata. Stay tuned for more on this, as time allows it.