Lori Phillips recently mentioned on the open-glam discussion list that Getty are starting to make high-resolution images of some of their public domain material available as part of their Open Content Program. The announcement mentions that metadata is included in each file, so I thought I'd take a look. It's Adobe Extensible Media Platform (XMP) aka RDF. Here's an example I pulled from The Portrait of Madame Brunet (I apologize if reading RDF as Turtle burns your eyes, but I find it much easier to read than the equivalent RDF/XML).

@prefix rdf:  .
@prefix Iptc4xmpCore:  .
@prefix Iptc4xmpExt:  .
@prefix dc:  .
@prefix photoshop:  .
@prefix xmpRights:  .


    Iptc4xmpCore:CreatorContactInfo [
        Iptc4xmpCore:CiAdrCity "Los Angeles" ;
        Iptc4xmpCore:CiAdrCtry "United States" ;
        Iptc4xmpCore:CiAdrExtadr "1200 Getty Center Drive" ;
        Iptc4xmpCore:CiAdrPcode "90049" ;
        Iptc4xmpCore:CiAdrRegion "California" ;
        Iptc4xmpCore:CiEmailWork "rights@getty.edu" ;
        Iptc4xmpCore:CiUrlWork "www.getty.edu"
    ] ;
    Iptc4xmpExt:ArtworkOrObject [
        a rdf:Bag ;
        rdf:_1 [
            Iptc4xmpExt:AOCreator [
                a rdf:Seq ;
                rdf:_1 "Édouard Manet"
            ] ;
            Iptc4xmpExt:AOSource "The J. Paul Getty Museum, Los Angeles" ;
            Iptc4xmpExt:AOSourceInvNo "2011.53" ;
            Iptc4xmpExt:AOTitle [
                a rdf:Alt ;
                rdf:_1 "Portrait of Madame Brunet"@x-default
            ]
        ] 
    ] ;
    photoshop:Source "The J. Paul Getty Museum, Los Angeles" ;
    xmpRights:UsageTerms [
        a rdf:Alt ;
        rdf:_1 "http://www.getty.edu/legal/image_request/"@x-default
    ] ;
    dc:creator [
        a rdf:Seq ;
        rdf:_1 "The J. Paul Getty Museum" 
    ] ;
    dc:date [
        a rdf:Seq ;
        rdf:_1 "2013-06-30T15:14:52"
    ] ;
    dc:description [
        a rdf:Alt ;
        rdf:_1 "Portrait of Madame Brunet; Édouard Manet, French, 1832 - 1883; France, Europe; about 1860 -1863, reworked by 1867; Oil on canvas; Unframed: 132.4 x 100 cm (52 1/8 x 39 3/8 in.), Framed: 153.7 x 121.9 x 7.6 cm (60 1/2 x 48 x 3 in.); 2011.53"@x-default
    ] ;
    dc:title [
        a rdf:Alt ;
        rdf:_1 "Portrait of Madame Brunet"@x-default
    ] .

The description is kind of heavy on information about the Getty, but light on information about the painting. For example it's not clear from the metadata that this is even a painting. You can see from the HTML detail page that there is a fair bit more about it available:

Édouard Manet (French, 1832 - 1883)
Portrait of Madame Brunet, about 1860 -1863, reworked by 1867, Oil on canvas
Unframed: 132.4 x 100 cm (52 1/8 x 39 3/8 in.)
Framed: 153.7 x 121.9 x 7.6 cm (60 1/2 x 48 x 3 in.)
The J. Paul Getty Museum, Los Angeles

Still, it's an incredible step forward to see these high resolution images being made available on the Web for download.