Extension:PagedTiffHandler/fr

Manuel des extensions MediaWiki

PagedTiffHandler État de la version : stable
Implémentation	Média
Description	Allows to display tiff-files
Auteur(s)	Hallo Welt! Medienwerkstatt GmbH for Wikimedia Deutschland e. V.
Dernière version	continuous updates
Politique de compatibilité	Versions ponctuelles alignées avec MediaWiki. Le master n'est pas compatible arrière.
MediaWiki	>= 1.42.0
PHP	7.0+
Modifie la base de données	Non
Licence	Licence publique générale GNU v2.0 ou supérieur
Téléchargement	Télécharger l'extension Git [?]: Télécharger la branche master de Git parcourir le dépôt (Phabricator · GitHub) historique des validations (commits) contributeurs du dépôt (GitHub) relecture du code
Paramètres $wgImageMagickIdentifyCommand $wgTiffUseExiv $wgTiffUseTiffinfo $wgTiffTiffinfoCommand $wgTiffIntermediaryScaleStep $wgTiffIdentifyRejectMessages $wgTiffIdentifyBypassMessages $wgTiffIdentifyRejectMessages $wgTiffTiffinfoRejectMessages $wgTiffMaxEmbedFiles $wgTiffMaxMetaSize $wgTiffErrorCacheTTL
Accroches fournies PagedTiffHandlerTiffData PagedTiffHandlerExifData PagedTiffHandlerRenderCommand
Téléchargements trimestriels	14 (Ranked 124th)
Utilisé par les wikis publics	922 (Ranked 261st)
Traduire l’extension PagedTiffHandler sur translatewiki.net si elle y est disponible
Problèmes	Tâches ouvertes · Signaler un bogue

The PagedTiffHandler extension allows to upload and display tiff-files into your wiki. It can handle multi-paged images and render them into thumbnails on per page basis.

Utilisation

You can embed images using standard image syntax. Additionally, there are two new parameters:

Paramètre	Exemple	Fonction
page	[[Image:Test.tiff|page=2]]	Renders a thumbnail of the second page of test.tiff. Page numbers start with 1. Default value is 1.
lossy	[[Image:Test.tiff|lossy=false]]	If set to false, thumbnails are being rendered as png, otherwise as jpg. If no value is set, PagedTiffHandler determines the value based on the presence of an alpha channel. If alpha is there, thumbnail is rendered as png. Possible values for jpg: '1', 'true' and 'lossy'. Possible values for png: '0', 'false' and 'lossless'.

Pré-requis

Requis

Paquet	Description	Lien
"imagemagick" for identify	Réalise le redimensionnement dynamique des images et la génération des vignette	www.imagemagick.org

Type the following in your shell to see if you have the above installed first:

which identify

Requis (optionnel)

Package	Description	Link
"exiv2" for exiv2	Exiv2 is a Cross-platform C++ library and a command line utility to manage image metadata. Provides support to retrieve EXIF from TIFF files.	www.exiv2.org
"libtiff-tools" for tiffinfo	Identify and retrieve basic TIFF metadata (more efficient than ImageMagick)	www.simplesystems.org/libtiff/

Type the following in your shell to see if you have the above installed first:

which exiv2 tiffinfo

For additional performance on very large TIFF files, you might want to install and configure the VipsScaler extension.

Installation

• Téléchargez et placez le(s) fichier(s) dans un répertoire appelé PagedTiffHandler dans votre dossier extensions/.
  Les développeurs et les contributeurs au code doivent à la place installer l'extension à partir de Git en utilisant:cd extensions/
git clone https://gerrit.wikimedia.org/r/mediawiki/extensions/PagedTiffHandler
• Ajoutez le code suivant à la fin de votre fichier LocalSettings.php  :

  wfLoadExtension( 'PagedTiffHandler' );
  

• Configurez si nécessaire.
•  Fait – Accédez à Special:Version sur votre wiki pour vérifier que l'extension a bien été installée.

Configuration

PagedTiffHandler depends on various external programs in order to process Tiff images.

• ImageMagick is used to reject/accept the image and render thumbail images. PagedTiffHandler will not work on any locally uploaded image without ImageMagick.
• tiffinfo can be used to reject/accept the image instead of ImageMagick, but it does not provide rendering (optional).
• Exiv2 is used to extract image metadata (optional).
• VipsScaler extension can be used for fast processing of large image files (optional).

Example configuration:

// Path to identify
$wgImageMagickIdentifyCommand = '/usr/bin/identify';
// Use exiv2? if false, MediaWiki's internal EXIF parser will be used
$wgTiffUseExiv = false;
// Path to exiv2 (MediaWiki core configuration option)
$wgExiv2Command = '/usr/bin/exiv2';
// Use tiffinfo? if false, ImageMagick's identify command will be used
$wgTiffUseTiffinfo = false;
// Path to tiffinfo
$wgTiffTiffinfoCommand = '/usr/bin/tiffinfo';

When thumbnailing very large images to very small sizes, it can be better better to downscale to an intermediary size first, instead of resizing in one go. By default PagedTiffHandler will downsize images larger than $wgTiffIntermediaryScaleStep (2048 pixels wide by default) first to $wgTiffIntermediaryScaleStep before downsizing to even smaller dimensions.

Example configuration:

// For thumbnails smaller than this, first scale to this amount
// Set to 0 to disable
$wgTiffIntermediaryScaleStep = 2048;

PagedTiffHandler rejects images based on error messages of ImageMagick or tiffinfo. There are three options:

• Images are rejected if the error message matches $wgTiffIdentifyRejectMessages or $wgTiffTiffinfoRejectMessages
• Images are accepted without moaning if the error message matches $wgTiffIdentifyBypassMessages or $wgTiffTiffinfoBypassMessages
• In other cases, images are accepted but the error message is recorded in the image metadata.

Example configuration (all of the parameters show the default configuration):

$wgTiffIdentifyRejectMessages = [
	'/^identify: Compression algorithm does not support random access/',
	'/^identify: Old-style LZW codes, convert file/',
	'/^identify: Sorry, requested compression method is not configured/',
	'/^identify: ThunderDecode: Not enough data at scanline/',
	'/^identify: .+?: Read error on strip/',
	'/^identify: .+?: Can not read TIFF directory/',
	'/^identify: Not a TIFF/',
];

$wgTiffIdentifyBypassMessages = [
	'/^identify: .*TIFFReadDirectory/',
	'/^identify: .+?: unknown field with tag .+? encountered/'
];

PagedTiffHandler also checks a few parameters of the image in order to be able to control the necessary processing time.

Example configuration:

// Maximum number of embedded files in tiff image
$wgTiffMaxEmbedFiles = 10000;
// Maximum size of meta data
$wgTiffMaxMetaSize = 64*1024; // 64kB

When thumbnailing fails for an image, PagedTiffHandler will not try again to render this image for some time. The setting below controls after how many seconds thumbnailing may be tried again.

Example configuration:

// TTL of Cacheentries for Errors
$wgTiffErrorCacheTTL = 84600;

Defaults

All of the above shown parameters are set as default in the configuration of the extension.

See also

• Extension:PdfHandler/fr