To provide additional useful facets and filtering of Europeana resources the addition of technical metadata at the level of the WebResource, which was currently absent from EDM, is needed. This specification applies to five media types which Europeana currently supports, namely: Sound, Video, Text, Image and 3D objects. This profile lists the properties that will apply to the WebResource class and an additional class that were defined to support such functionality.
A minimal approach has been adopted to the addition of properties to EDM. Not all functions require the addition of a specific property. Consider for example the filtering of Europeana objects based on the presence of a usable thumbnail. This can be detected by checking for the presence of a URL in the “edm:preview” property (and the resource flagged accordingly in a search system) without the need for a specific EDM property to hold that flag in Europeana’s reference data.
Some values can be used to generate further values and, depending on the stage in the processing of data where this happens, a property may be needed to record the output. For example, the orientation of an image will be generated by processing numeric values given in the height and width properties, giving the result as “Portrait” or “Landscape”. A few properties have been created in the EDM namespace even though similar properties already exist elsewhere (e.g. Exif and EBUCore). This is because the allowable values did not match our requirements at this time (e.g. EDM needs literal values in some cases). These properties are: “edm“edm:hasColorSpace”hasColorSpace”, “edm“edm:componentColor”componentColor”, “edm“edm:spatialResolution” spatialResolution” and “edm“edm:codecName”codecName”.
Properties
All the properties defined below should be applied to edm:WebResource.
edm:codecName
URI
http://www.europeana.eu/schemas/edm/codecName
Label
Codec
Definition
The name of a device or computer program capable of encoding or decoding a digital data stream or signal (i.e. coder-decoder)
The duration of a track or a signal expressed in ms.
Subproperty of
ebucore:duration
Domain
edm:WebResource
Obligation & Occurrence
Optional (Minimum: 0, Maximum: 1)
Example
270000
Comment
An implementation decision was made to use this property instead of a more normative property such as “ebucore:durationNormalPlayTime” so that a duration could be expressed as a number. Used for Video and Sound.
A significant color present in an image. The colors must be taken from the CSS3 standard color palette and are expressed as a hexadecimal binary value.
This is used to indicate that a web resource contains searchable, machine readable text. In the context of this EDM extension, “rdf:type” has been introduced to be used in relation with classes relevant for this extension, especially “edm:FullTextResource”.
A resource that has machine readable full text content.
Subclass of
edm:InformationResource
Example
Typically this could be the result of a newspaper that has been digitised as an image or PDF file and then OCRed to produce a separate file with the full text.
Comment
When full-text is available for a digital object it must be represented in a specific class. This is because in some cases the WebResource that provides the view of the object to end-users does not contain the full-text in machine readable form. This is taken from the Europeana Libraries report on full-text.
Document history:
Robina Clayphan, Hugo Manguinhas - Final version after review
Hugo Manguinhas, Antoine Isaac - Additional comments incorporated
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An overview of all the technical metadata facets in Europeana Collections can be found at Documentation on the Europeana Search APIAPI. The content tiers, i.e. the quality of a media resource as specified in the Europeana Publishing Framework, are calculated on the basis of the technical metadata.
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Media Formats/Mime Types
A MIME type (also known as a Multipurpose Internet Mail Extension) is a standard that indicates the format of a file. It is a fundamental characteristic of a digital resource that influences its ability to be accessed and used over time.
The purpose of this section is to provide a list of MIME types corresponding to different types of content/media that are supported or not by Europeana.
Media formats supported on Europeana Collections
Format Name
Mime-type
File Extension(s)
Image
JPEG
image/jpeg
.jpeg
PNG
image/png
.png
GIF
image/gif
.gif
Generic Bitmap
image/bmp
.bmp
Microsoft Bitmap
image/x-ms-bmp
.bmp
Text
PDF
application/pdf
.pdf
Video
MPEG-4 Video
video/mp4
.mp4
Open Web Media Project – Video
video/webm
.webm
M4v
video/x-m4v
.m4v
Quicktime video
video/quicktime
.mov, .qt
Audio
MP3 or other MPEG format
audio/mpeg
.mp3
Waveform Audio
audio/x-wav
.wav, .wave
Media formats not supported in Europeana Collections
Not all the links to media resources that Europeana receives from data providers can be displayed in the Europeana Collections portal, however these are still made available for download to our users for reuse. The respective media formats (and mime-types) are presented in the table below.