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Nepomuk File Ontology (NFO)

Nepomuk File Ontology (NFO) — About files and other desktop resources.

Synopsis

@prefix nfo: <http://tracker.api.gnome.org/ontology/v3/nfo#>

Classes

Application, Archive, ArchiveItem, Attachment, Audio, Bookmark, BookmarkFolder, CompressionType, Cursor, DataContainer, DeletedResource, Document, EBook, EmbeddedFileDataObject, Equipment, Executable, FileDataObject, FileHash, Filesystem, FilesystemImage, Folder, Font, GameImage, HardDiskPartition, HelpDocument, HtmlDocument, Icon, Image, ImageCategory, Media, MediaFileListEntry, MediaList, MediaStream, MindMap, Note, OperatingSystem, Orientation, PaginatedTextDocument, PlainTextDocument, Presentation, RasterImage, RegionOfInterest, RegionOfInterestContent, RemoteDataObject, RemotePortAddress, Software, SoftwareApplication, SoftwareCategory, SoftwareItem, SoftwareService, SourceCode, Spreadsheet, TextDocument, Trash, VectorImage, Video, Visual, WebHistory, Website

Additional Properties

belongsToContainer, isBootable, isContentEncrypted, depiction

Class Details

Application

Description

An application

Archive

Description

A compressed file. May contain other files or folder inside.

Properties

Name Type Notes Description

uncompressedSize

integer  

Uncompressed size of the content of a compressed file.


ArchiveItem

Description

A file entity inside an archive.

Properties

Name Type Notes Description

isPasswordProtected

boolean  

States if a given resource is password-protected.


Attachment

Description

A file attached to another data object. Many data formats allow for attachments: emails, vcards, ical events, id3 and exif...

Audio

Description

A file containing audio content

Notify iconThis class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nie:InformationElement 
        nfo:Media 
        ╰── nfo:Audio 

Properties

Name Type Notes Description

audioOffset

double  

Specifies the start offset of this resource within a larger file, such as a single song within a recording of a radio broadcast or a CD rip.

averageAudioBitrate

double  

The average overall bitrate of a media container. (i.e. the size of the piece of media in bits, divided by it's duration expressed in seconds).

bitsPerSample

integer This property extends nfo:bitDepth

Amount of bits in each audio sample.

channels

integer  

Number of channels. This property is to be used directly if no detailed information is necessary. Otherwise use more detailed subproperties.

frontChannels

integer This property extends nfo:channels

Number of front channels.

gain

integer  

Gain of media

lfeChannels

integer This property extends nfo:channels

Number of Low Frequency Expansion (subwoofer) channels.

peakGain

integer  

Peak Gain of media

rearChannels

integer This property extends nfo:channels

Number of rear channels.

sampleCount

integer This property extends nfo:count

The amount of samples in an audio clip.

sampleRate

double  

The amount of audio samples per second.

sideChannels

integer This property extends nfo:channels

Number of side channels


Bookmark

Description

A bookmark of a webbrowser. Use nie:title for the name/label, nie:contentCreated to represent the date when the user added the bookmark, and nie:contentLastModified for modifications. nfo:bookmarks to store the link.

Notify iconThis class emits notifications about changes, and can be monitored using TrackerNotifier.

Properties

Name Type Notes Description

bookmarks

DataObject This property extends nie:links

The address of the linked object. Usually a web URL.

characterPosition

integer  

Character position of the bookmark

pageNumber

integer  

Page linked by the bookmark

streamDuration

integer    

streamPosition

integer  

Stream position of the bookmark, suitable for e.g. audio books. Expressed in milliseconds


BookmarkFolder

Description

A folder with bookmarks of a webbrowser. Use nfo:containsBookmark to relate Bookmarks. Folders can contain subfolders, use containsBookmarkFolder to relate them.

Notify iconThis class emits notifications about changes, and can be monitored using TrackerNotifier.

Properties

Name Type Notes Description

containsBookmark

Bookmark This property extends nie:hasLogicalPartThis property can have multiple values.

The folder contains a bookmark.

containsBookmarkFolder

BookmarkFolder This property extends nie:hasLogicalPartThis property can have multiple values.

The folder contains a bookmark folder.


CompressionType

Description

Type of compression. Instances of this class represent the limited set of values allowed for the nfo:compressionType property.

Cursor

Description

A Cursor.

Class hierarchy

    nie:InformationElement 
        nfo:Media 
        ╰── nfo:Visual 
            ╰── nfo:Image 
                ╰── nfo:RasterImage 
                    ╰── nfo:Cursor 

DataContainer

Description

A superclass for all entities, whose primary purpose is to serve as containers for other data object. They usually don't have any 'meaning' by themselves. Examples include folders, archives and optical disc images.

Notify iconThis class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nie:InformationElement ──┐
        nfo:DataContainer ───┤
        ├── nfo:Folder       │
        ├── nfo:Filesystem   │
        ├── nfo:Trash        │
        ├── nfo:Archive      │
        ╰── nfo:ImageCategory   │
                                   └── nfo:SoftwareCategory 

DeletedResource

Description

A file entity that has been deleted from the original source. Usually such entities are stored within various kinds of 'Trash' or 'Recycle Bin' folders.

Properties

Name Type Notes Description

deletionDate

dateTime  

The date and time of the deletion.

originalLocation

string  

The original location of the deleted resource.


Document

Description

A generic document. A common superclass for all documents on the desktop.

Notify iconThis class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nie:InformationElement 
        nfo:Document 
        ├── nfo:TextDocument 
        ├── nfo:Presentation 
        ├── nfo:Spreadsheet 
        ├── nfo:MindMap 
        ├── nfo:Note 
        ╰── nfo:HelpDocument 

Properties

Name Type Notes Description

tableOfContents

string This property is full-text-indexed, and can be looked up through fts:match

Section titles and figure descriptions of the document.


EBook

Description

Books which can be electronically viewed

EmbeddedFileDataObject

Description

A file embedded in another data object. There are many ways in which a file may be embedded in another one. Use this class directly only in cases if none of the subclasses gives a better description of your case.

Properties

Name Type Notes Description

encoding

string  

The encoding used for the Embedded File. Examples might include BASE64 or UUEncode


Equipment

Description

The equipment used to create media

Properties

Name Type Notes Description

equipmentSoftware

string  

The software of the equipment

manufacturer

string  

The manufacturer of the equipment

model

string  

The model of the equipment


Executable

Description

An executable file.

FileDataObject

Description

A resource containing a finite sequence of bytes with arbitrary information, that is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available for programs to use after the current program has finished.

Notify iconThis class emits notifications about changes, and can be monitored using TrackerNotifier.

Properties

Name Type Notes Description

fileCreated

dateTime This property extends nie:created

File creation date

fileLastAccessed

dateTime This property extends dc:date

Time when the file was last accessed.

fileLastModified

dateTime This property extends dc:date

last modification date

fileName

string This property is full-text-indexed, and can be looked up through fts:match

Name of the file, together with the extension

fileOwner

Contact  

The owner of the file as defined by the file system access rights feature.

fileSize

integer This property extends nie:byteSize

The size of the file in bytes. For compressed files it means the size of the packed file, not of the contents. For folders it means the aggregated size of all contained files and folders

hasHash

FileHash  

Links the file with it's hash value.

permissions

string  

A string containing the permissions of a file. A feature common in many UNIX-like operating systems.


FileHash

Description

A fingerprint of the file, generated by some hashing function.

Class hierarchy

    rdfs:Resource 
        nfo:FileHash 

Properties

Name Type Notes Description

hashAlgorithm

string  

Name of the algorithm used to compute the hash value. Examples might include CRC32, MD5, SHA, TTH etc.

hashValue

string  

The actual value of the hash.


Filesystem

Description

A filesystem. Examples of filesystems include hard disk partitions, removable media, but also images thereof stored in files.

FilesystemImage

Description

An image of a filesystem. Instances of this class may include CD images, DVD images or hard disk partition images created by various pieces of software (e.g. Norton Ghost)

Folder

Description

A folder/directory. Examples of folders include folders on a filesystem and message folders in a mailbox.

Font

Description

A font.

Properties

Name Type Notes Description

fontFamily

string This property is full-text-indexed, and can be looked up through fts:match

The name of the font family.

foundry

Contact This property extends nco:creator

The foundry, the organization that created the font.


GameImage

Description

A game image. This is a Tracker extension

HardDiskPartition

Description

A partition on a hard disk

HelpDocument

Description

User guides and similar to assist the user

HtmlDocument

Description

A HTML document, may contain links to other files.

Icon

Description

An Icon (regardless of whether it's a raster or a vector icon. A resource representing an icon could have two types (Icon and Raster, or Icon and Vector) if required.

Class hierarchy

    nie:InformationElement 
        nfo:Media 
        ╰── nfo:Visual 
            ╰── nfo:Image 
                ╰── nfo:Icon 

Image

Description

A file containing an image.

Notify iconThis class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nie:InformationElement 
        nfo:Media 
        ╰── nfo:Visual 
            ╰── nfo:Image 
                ├── nfo:RasterImage 
                ├── nfo:VectorImage 
                ╰── nfo:Icon 

Properties

Name Type Notes Description

depicts

Resource This property can have multiple values.

Relates an image to the information elements it depicts.

hasRegionOfInterest

RegionOfInterest This property can have multiple values.

Link an element with a defined region

horizontalResolution

integer  

Horizontal resolution of an image (if printed). Expressed in DPI.

orientation

Orientation    

verticalResolution

integer  

Vertical resolution of an Image (if printed). Expressed in DPI


ImageCategory

Description

A image category

Predefined instances

nfo:ImageCategory has the following predefined instances:

  • nfo:image-category-screenshot


Media

Description

A piece of media content. This class may be used to express complex media containers with many streams of various media content (both aural and visual).

Class hierarchy

    nie:InformationElement 
        nfo:Media 
        ├── nfo:Visual 
        ╰── nfo:Audio 

Properties

Name Type Notes Description

averageBitrate

double  

The average overall bitrate of a media container. (i.e. the size of the piece of media in bits, divided by it's duration expressed in seconds).

bitDepth

Literal  

A common superproperty for all properties signifying the amount of bits for an atomic unit of data. Examples of subproperties may include bitsPerSample and bitsPerPixel

bitrateType

string  

The type of the bitrate. Examples may include CBR and VBR.

codec

string  

The name of the codec necessary to decode a piece of media.

compressionType

CompressionType  

The type of the compression. Values include, lossy and lossless.

count

integer  

A common superproperty for all properties signifying the amount of atomic media data units. Examples of subproperties may include sampleCount and frameCount.

duration

integer  

Duration of a media piece.

encodedBy

string  

The contains the name of the person or organisation that encoded the media

equipment

Equipment  

Equipment used to create the media

genre

string This property is full-text-indexed, and can be looked up through fts:match

Genre of media

hasMediaStream

DataObject This property extends nie:hasPartThis property can have multiple values.

Connects a media container with a single media stream contained within.

lastPlayedPosition

integer  

Position in the media (in seconds) where the play was paused. Positive number, being 0 the beginning of the media.


MediaFileListEntry

Description

A single node in the list of media files contained within an MediaList instance. This class is intended to provide a type all those links have. In valid NRL untyped resources cannot be linked. There are no properties defined for this class but the application may expect rdf:first and rdf:last links. The former points to the DataObject instance, interpreted as Media the latter points at another MediaFileListEntr. At the end of the list there is a link to rdf:nil.

Properties

Name Type Notes Description

entryUrl

string  

URL to the element in certain position of the list

listPosition

double  

Position of an entry in a list. Double, to optimize the poor insertions


MediaList

Description

A file containing a list of media files.e.g. a playlist

Properties

Name Type Notes Description

entryCounter

integer  

Number of entries in the list. Optimize some common queries

hasMediaFileListEntry

MediaFileListEntry This property can have multiple values.

This property is intended to point to an RDF list of MediaFiles.

listDuration

integer  

Sum of the duration of all items in the list. Optimize some common queries. In seconds

mediaListEntry

InformationElement This property can have multiple values.

A certain item belongs to a media list. This can reflect that a song is in a playlist, an image or video in an Album


MediaStream

Description

A stream of multimedia content, usually contained within a media container such as a movie (containing both audio and video) or a DVD (possibly containing many streams of audio and video). Most common interpretations for such a DataObject include Audio and Video.

MindMap

Description

A MindMap, created by a mind-mapping utility. Examples might include FreeMind or mind mapper.

Class hierarchy

    nie:InformationElement 
        nfo:Document 
        ╰── nfo:MindMap 

Note

Description

Usually small document with snippets, reminders or frequenly used content.

Class hierarchy

    nie:InformationElement 
        nfo:Document 
        ╰── nfo:Note 

OperatingSystem

Description

An OperatingSystem

Orientation

Description

Orientation enum

Class hierarchy

    rdfs:Resource 
        nfo:Orientation 

Predefined instances

nfo:Orientation has the following predefined instances:

  • nfo:orientation-left

  • nfo:orientation-right-mirror

  • nfo:orientation-right

  • nfo:orientation-left-mirror

  • nfo:orientation-bottom-mirror

  • nfo:orientation-bottom

  • nfo:orientation-top-mirror

  • nfo:orientation-top


PaginatedTextDocument

Description

A file containing a text document, that is unambiguously divided into pages. Examples might include PDF, DOC, PS', DVI etc.

Properties

Name Type Notes Description

pageCount

integer  

Number of pages.


PlainTextDocument

Description

A file containing plain text (ASCII, Unicode or other encodings). Examples may include TXT, HTML, XML, program source code etc.

Presentation

Description

A Presentation made by some presentation software (Corel Presentations, OpenOffice Impress, MS Powerpoint etc.)

RasterImage

Description

A raster image.

Class hierarchy

    nie:InformationElement 
        nfo:Media 
        ╰── nfo:Visual 
            ╰── nfo:Image 
                ╰── nfo:RasterImage 
                    ╰── nfo:Cursor 

RegionOfInterest

Description

Area on an image with relevant content. Following the spec in http://www.metadataworkinggroup.org

Properties

Name Type Notes Description

regionOfInterestHeight

double  

Height of the region. It is normalized (values between 0 and 1) to the total height of the picture.

regionOfInterestType

RegionOfInterestContent  

The content of a region can be one of the predefined types in the spec

regionOfInterestWidth

double  

Width of the region. It is normalized (values between 0 and 1) to the total width of the picture.

regionOfInterestX

double  

Coordinate X where the region starts. It is normalized (values between 0 and 1) to the width of the picture. Starting in the upper left corner.

regionOfInterestY

double  

Coordinate y where the region starts. It is normalized (values between 0 and 1) to the height of the picture. Starting in the upper left corner.

roiRefersTo

InformationElement  

Link to an item that is represented in the region. The 'type' of the region can give a clue of what exact content is linked in this property


RegionOfInterestContent

Description

Content in the area. There is a predefined set of contents in the spec: http://www.metadataworkinggroup.org

Predefined instances

nfo:RegionOfInterestContent has the following predefined instances:

  • nfo:roi-content-undefined

  • nfo:roi-content-barcode

  • nfo:roi-content-focus

  • nfo:roi-content-pet

  • nfo:roi-content-face


RemoteDataObject

Description

A file data object stored at a remote location. Don't confuse this class with a RemotePortAddress. This one applies to a particular resource, RemotePortAddress applies to an address, that can have various interpretations.

RemotePortAddress

Description

An address specifying a remote host and port. Such an address can be interpreted in many ways (examples of such interpretations include mailboxes, websites, remote calendars or filesystems), depending on an interpretation, various kinds of data may be extracted from such an address.

Software

Description

A piece of software. Examples may include applications and the operating system. This interpretation most commonly applies to SoftwareItems.

Properties

Name Type Notes Description

conflicts

Software  

States that a piece of software is in conflict with another piece of software.

softwareCmdLine

string  

Command to launch the software

softwareIcon

Image  

Icon of the software

supercedes

Software  

States that a piece of software supercedes another piece of software.


SoftwareApplication

Description

An application

Notify iconThis class emits notifications about changes, and can be monitored using TrackerNotifier.


SoftwareCategory

Description

A software category

Class hierarchy

    nie:InformationElement nie:InformationElement ──┐
        nfo:DataContainer     ──────────────────────┤
    ────────────────────────────────────────────────┤
                                                    └── nfo:SoftwareCategory 

Properties

Name Type Notes Description

softwareCategoryIcon

Image  

Icon of the software


SoftwareItem

Description

A DataObject representing a piece of software. Examples of interpretations of a SoftwareItem include an Application and an OperatingSystem.

SoftwareService

Description

A service published by a piece of software, either by an operating system or an application. Examples of such services may include calendar, addresbook and mailbox managed by a PIM application. This category is introduced to distinguish between data available directly from the applications (Via some Interprocess Communication Mechanisms) and data available from files on a disk. In either case both DataObjects would receive a similar interpretation (e.g. a Mailbox) and wouldn't differ on the content level.

SourceCode

Description

Code in a compilable or interpreted programming language.

Properties

Name Type Notes Description

commentCharacterCount

integer  

The amount of character in comments i.e. characters ignored by the compiler/interpreter.

definesClass

string  

Name of a class defined in the source code file.

definesFunction

string  

A name of a function/method defined in the given source code file.

definesGlobalVariable

string  

Name of a global variable defined within the source code file.

programmingLanguage

string  

Indicates the name of the programming language this source code file is written in. Examples might include 'C', 'C++', 'Java' etc


Spreadsheet

Description

A spreadsheet, created by a spreadsheet application. Examples might include Gnumeric, OpenOffice Calc or MS Excel.

TextDocument

Description

A text document

Properties

Name Type Notes Description

characterCount

integer  

The amount of characters in the document.

lineCount

integer  

The amount of lines in a text document

wordCount

integer  

The amount of words in a text document.


Trash

Description

Represents a container for deleted files, a feature common in modern operating systems.

VectorImage

Description

A vector image (e.g. SVG)

Class hierarchy

    nie:InformationElement 
        nfo:Media 
        ╰── nfo:Visual 
            ╰── nfo:Image 
                ╰── nfo:VectorImage 

Video

Description

A video file.

Notify iconThis class emits notifications about changes, and can be monitored using TrackerNotifier.

Class hierarchy

    nie:InformationElement 
        nfo:Media 
        ╰── nfo:Visual 
            ╰── nfo:Video 

Properties

Name Type Notes Description

averageVideoBitrate

double  

The average overall bitrate of a media container. (i.e. the size of the piece of media in bits, divided by it's duration expressed in seconds).

frameCount

integer This property extends nfo:count

The amount of frames in a video sequence.

frameRate

double  

Amount of video frames per second.


Visual

Description

File containing visual content.

Class hierarchy

    nie:InformationElement 
        nfo:Media 
        ╰── nfo:Visual 
            ├── nfo:Image 
            ╰── nfo:Video 

Properties

Name Type Notes Description

aspectRatio

double  

Visual content aspect ratio. (Width divided by Height)

colorDepth

integer This property extends nfo:bitDepth

Amount of bits used to express the color of each pixel.

heading

double  

Specifies the direction of travelling while capturing image/video. The range of values from 0.00 to 359.99 (where 0 is due North, 90 is East, 180 South and 270 is West)

height

integer  

Visual content height in pixels.

interlaceMode

boolean  

True if the image is interlaced, false if not.

tilt

double  

Vertical inclination of the camera while capturing the image, in angles starting on 0 as horizontal, positive numbers pointing up, negative angles pointing down

width

integer  

Visual content width in pixels.


WebHistory

Description

A web history entry

Notify iconThis class emits notifications about changes, and can be monitored using TrackerNotifier.

Properties

Name Type Notes Description

domain

string    

uri

string    

Website

Description

A website, usually a container for remote resources, that may be interpreted as HTMLDocuments, images or other types of content.

Property Details

Additional properties for nie:DataObject

Description

Properties this ontology defines which can describe nie:DataObject resources.

Properties

Name Type Notes Description

belongsToContainer

DataContainer This property extends nie:isPartOf

Models the containment relations between Files and Folders (or CompressedFiles).


Additional properties for nie:InformationElement

Description

Properties this ontology defines which can describe nie:InformationElement resources.

Properties

Name Type Notes Description

isBootable

boolean  

True when the file is bootable, for example like an ISO or other disc images

isContentEncrypted

boolean  

Might change (IE of DataObject property?)


Additional properties for rdfs:Resource

Description

Properties this ontology defines which can describe rdfs:Resource resources.

Properties

Name Type Notes Description

depiction

Image This property can have multiple values.

Relates an information element to an image which depicts said element.

Credits and Copyright

Authors:
  • Tracker Developers
  • Ludger van Elst, DFKI, <elst@dfki.uni-kl.de>
  • Michael Sintek, DFKI, <michael.sintek@dfki.de>
  • Leo Sauermann, DFKI, <leo.sauermann@dfki.de>
  • Antoni Mylka, DFKI, <antoni.mylka@dfki.de>
Editors:
  • Antoni Mylka, DFKI, <antoni.mylka@dfki.de>
  • Tracker developers (translation into turtle)
Contributors:
  • Christiaan Fluit, Aduna, <christiaan.fluit@aduna-software.com>
  • Evgeny 'phreedom' Egorochkin, KDE Strigi Developer, <stexx@mail.ru>
Upstream:

Upstream version

ChangeLog:

Tracker changes

Copyright:

© 2007 DFKI © 2009 Nokia. The ontologies are made available under the terms of NEPOMUK software license (FIXME verify)