Extension:CommonsMetadata/it

L'estensione CommonsMetadata è un tentativo di estrarre metadati dalle pagine di Wikimedia Commons. Aggiunge alcune informazioni extra all'API imageinfo, basate su template e categorie presenti nella descrizione dell'immagine. It adds some extra information to the API, based on templates and categories in the image description. It is used by a number of extensions / tools (such as, , , Mobile-Content-Service (MCS)) to provide better lightboxes or image selection dialogs.

L'estensione nella sua forma attuale è intesa come soluzione temporanea, da sostituirsi con Wikidata su Commons.



Motivazioni e scelte progettuali
See wikitech-l/2013-August/071593.html

Le assunzioni fatte per questa estensione sono le seguenti.


 * Ad un certo punto in futuro, wikidata prenderà in mano la gestione dei metadati su commons. Per evitare cambiamenti troppo marcati, che verrebbero subito modificati nuovamente, l'estensione dovrebbe lavorare con i metadati di commons, come avviene attualmente (senza introdurre nuove funzioni di analisi). Da qui lo screen scraping.


 * The content of many of the fields on a commons description page include rich formatting (In particular: Links, italics, bold. In some cases more complex things like embedded images)
 * As a result, extension outputs parsed html (wikitext sucks, plain text doesn't capture the data)
 * Futhermore, the data tends to be formatted for human display, rather than (for example) machine formatted dates. When the date field says something like "circa 1600s", its hard to convert that to a precise date (otoh, many examples can be).
 * To carry that forward, also apply formatting to exif metadata, which is controlled on wiki (For example, commons links the camera name to a wikipedia article)


 * If we can't extract info from the description page, but the file has the author tagged in exif/XMP/iptc metadata, we should use that as a fallback.
 * Ideally such a system would be as commons-inspecific as possible, with the commons and non-commons part separated.


 * Commons description pages have multilingual descriptions. Lots of users probably just want one language.
 * In this implementation, it applies per language conventions to dates and things. Additionally for explicitly multi-lingual fields (description), there is an option to return all, or just a single language. Even in single language mode, some things are still language specific (like the thousands seperator on numbers)

Testing
When testing with remote images (e.g. Commons images if you have enabled ), you can set  to force CommonsMetadata to parse the description page of the image and extract the metadata (normally, if the remote repository had CommonsMetadata installed as well, it would just copy the API output from there).

Uso
Usa l'API imageinfo ed inserisci  come proprietà dell'informazione dell'immagine specificata attraverso il parametro.

Esempio di utilizzo:
 * https://commons.wikimedia.org/w/api.php?action=query&prop=imageinfo&format=xml&iiprop=extmetadata&iilimit=10&titles=File%3ACommon%20Kingfisher%20Alcedo%20atthis.jpg


 * https://commons.wikimedia.org/w/api.php?action=query&prop=imageinfo&format=json&iiprop=extmetadata&iilimit=10&titles=File%3ACommon%20Kingfisher%20Alcedo%20atthis.jpg

Visualizza questo esempio nella API sandbox:
 * https://www.mediawiki.org/wiki/Special:ApiSandbox#action=query&prop=imageinfo&format=xml&iiprop=extmetadata&iilimit=10&titles=File%3ACommon%20Kingfisher%20Alcedo%20atthis.jpg


 * https://www.mediawiki.org/wiki/Special:ApiSandbox#action=query&prop=imageinfo&format=json&iiprop=extmetadata&iilimit=10&titles=File%3ACommon%20Kingfisher%20Alcedo%20atthis.jpg

Returned data
The extension currently provides the following items in the  field of the response (the field names were chosen, where possible, to follow the IPTC-IIM format used in EXIF headers):

Data based on machine-readable data in the Information template:


 * ImageDescription - image description
 * Artist - author name (might contain complex HTML, multiple authors etc)
 * Credit - source
 * DateTimeOriginal - time of creation (space-separated ISO 8601 timestamp whenever possible, but can be any other textual description of a date, possibly with HTML mixed in)
 * ObjectName - title (for a book/painting; otherwise just the file name)
 * Permission - contents of the Permission field of the template. Can be a lot of things (license template, OTRS id, details on how to attribute...)
 * AuthorCount - the number of templates with authors (e.g. Book, Photograph...). The number of actual authors might be higher if a template describes multiple authors in a single string.

Data based on machine-readable data in the Location template:


 * GPSLatitude - latitude
 * GPSLongitude - longitude
 * GPSMapDatum - coordinate type (only  supported for now)

Data based on machine-readable data in the license template:


 * LicenseShortName - short human-readable license name
 * LicenseUrl
 * UsageTerms
 * Copyrighted -  or   (for public domain images)

For multi-licensed images these values are currently unreliable.


 * Attribution - custom attribution that should replace Artist + Credit (can also originate from the Information template)
 * AttributionRequired - booleanish (T86726), tells whether there is a legal requirement to attribute
 * NonFree - booleanish, true means the image is not under a free license. (Used for non-Commons images only.)

Other data: Based on parsing category names, probably won't work for images not hosted on Commons. (Based on the nuke template, probably not reliable outside Commons.) It contains a deletion reason, but it is phrased to be applicable for a log entry, so it might be misleading (e.g. past tense when actually it is not yet decided whether the image will be deleted).
 * CommonsMedadataExtension - contains the metadata parser version number; mostly for internal use
 * License - a best guess at the license of the image (mostly for internal use by MediaViewer, might change; LicenseShortName is probably more reliable)
 * Categories - a -separated list of the categories of the image.
 * Assessments - a -separated list of the assessments of the image (currently five values are supported: poty, potd, featured, quality, valued).
 * Restrictions - reuse restrictions such as trademarks or personality rights; an array of keywords (the class names from this table, without the  prefix). See also the restrict-* icons in MediaViewer.
 * DeletionReason - if set, the template is being considered for deletion.



Vedi anche

 * Gestione dei metadati dei file
 * - attualmente l'utente principale delle informazioni fornite da CommonsMetadata
 * Richiesta di commenti sulla gestione delle informazioni delle immagini
 * Richiesta di commenti sulla gestione delle informazioni delle immagini
 * Individuazione dei template sulle wiki locali con file caricati localmente – Descrive come preparare i template per estrarre i metadati e poi mostrarli quando si usa l'estensione MultimediaViewer