Photo Tagging

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Use of XMP Tags

With the addition of nested keywords and the use of Media Center expression language, Media Center can faily easily create nested XMP tags of the sort that are used by Windows Vista (e.g. Photo Gallery) and Adobe products (e.g. Photoshop Elements).

When they Keywords field is part of a View Scheme (see View Schemes) and the top level of the View Scheme is displayed in Standard View, using Panes, there will be a column at the top of the screen that displays keywords. Keyworlds will appear as nested when subkeywords are separated from the main keyword by "\". For example "Location\Illinios".

For example one can have Genre, Event, Location, Places, and People as keywords with the data they would contain following a backslash. In this way the same type of information that would be stored in custom fields can be stored in nested keywords.

Note that nested keywords in Media Center use the backslash, but the comparable delimiter in XMP tagging is a forward slash. MC addresses this issue by changing backslashes to foward slashes when writing XMP tags. [Query: does the reverse happen when MC reads XMP tags?]

To convert a series of MC fields to XMP tags for group of photos (or one's whole library), the following method can be used:

  • View Details
  • Click on a column heading and choose Columns and make sure Keywords is checked to that the Keywords column is displayed
  • Select the group of images you want to add add XMP tags to
  • Mouse over the Keywords column and press F2
  • Enter an expression like the following (which converts the fields mentioned above to nested keywords:

=if(IsEmpty([Genre]),,Genre\[Genre];)if(IsEmpty([Event]),,Event\[Event];)if(IsEmpty([Location]),,Location\[Location];)if(IsEmpty([Places]),,Places\[Places];)if(IsEmpty([People]),,People\replace([People],;,;People\))

  • Hit Enter (Note: don't switch to another window dialog or it will be as if you hit enter.)

What's going on in the above expression:

[To come]

Use of IPTC Tags

The way the IPTC tags are read currently, any matched field that is not already being used is read from IPTC. This means once read, the IPTC tags won't be read again from that photo, unless the tags are cleared in MC. The IPTC and existing tags are not merged.

Here are the current IPTC tags being read, and MC tags they are mapped to (also subject to change):

  • BYLINE -> Artist
  • CREDITS -> Notes
  • DATECREATED ->[changed] Date
  • CITY STATE, COUNTRY ->(combined) Places
  • COPYRIGHTNOTICE ->Copyright (read only)
  • CAPTION ->(same: no longer Comment)
  • CATEGORY->Genre
  • KEYWORDS->(same)

Information that can't be stored in those tags gets saved in MJMD tags.

Keywords from IPTC maps to MC's Keywords. IPTC Keywords is the only thing Windows Photo Gallery seems to recognize.

MC saves IPTC tags, except for Places, to any JPEG it tags.

EXIF Tags

MC populates the Aperture, Camera, Date, Flash, Focal Length Format, ISO and Shutter Speed fields from EXIF information in the JPEG file while importing that file.


MC Photo Editor Effect on Tags

Is file metadata/tagging preserved? EXIF?

It depends on what you do, and how MC is setup. If you perform a "save as.." in order to preserve the original file, a new file is created, and it has absolutely no metadata whatsoever. No file tags, and no database info. It will be a brand new file that will need to be tagged from scratch. If you simply save the edits over the top of the original file, then you still end up with a brand new file with no metadata whatsoever, but you will still have any previous tagging info for that file in your MC database. You can use the update tags from library to re-write the tags. EXIF info is permanently lost. Also, in this scenario, if you have auto import watching the folder the image resides in, you need to get that tag update done before Otto wakes up (either be quick, or unwatch the foder) because Otto will see that, essentially new, file as having received external changes and promptly set about updating things!


Practical Advice for Tagging Photos

  • Make sure Media Center isn't in a read only mode or you risk tag changes being lost
  • Use semicolons between people's names in a People field to make sure they are interpreted as discrete tags
  • Set relevant columns to display, e.g. "Event", "People", "Location", "Places", "Genre"
  • Use Display View, close and then detach display for a larger view of the currently playing picture
  • View as thumbnails (using the slider to select a larger size than the default)
  • Use Tagging to apply tags to multiple photos that you have selected
  • People values can be tagged one at a time
  • When changing the People tags, the People window will only populate with existing values if the file is already part of the library, so best to import files before editing these tags
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