Extension:VipsScaler

Manuel des extensions MediaWiki

VipsScaler État de la version : stable
Implémentation	Média
Description	Allows to scale PNG and JPEG images using VIPS
Auteur(s)	Bryan Tong Minh (Bryandiscussion)
MediaWiki	1.19+
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 (GitHub) historique des validations (commits) contributeurs du dépôt (GitHub) relecture du code README
Paramètres $wgVipsCommand $wgVipsOptions $wgVipsTestExpiry $wgVipsExposeTestPage $wgVipsThumbnailerHost
Droits ajoutés vipsscaler-test
Accroches utilisées BitmapHandlerCheckImageArea BitmapHandlerTransform
Traduire l’extension VipsScaler sur translatewiki.net si elle y est disponible
Vérifier la matrice des utilisations et des versions.
Problèmes	Tâches ouvertes · Signaler un bogue

The VipsScaler extension is a wrapper around VIPS, a free image processing software. VIPS is a set of image manipulation tools specially designed for speed and low memory usage. This is useful for resizing large PNGs, and it improves the appearance of shrunken JPEGs.

The extension shells out to the vips binary. It can be configured to scale only certain files (for example: big PNGs) by configuring $wgVipsOptions.

VIPS installation

Install VIPS

Install VIPS. It can be downloaded from https://libvips.github.io/libvips or your OS repository (see below).

Debian / Ubuntu

$ apt-get install libvips-tools

If you want to build from source have a look at upstream documentation: https://libvips.github.io/libvips/install.html

(Wikimedia has packaged and uses a more recent version for Ubuntu 12.04 at apt.wikimedia.org)

Mac OS X

homebrew

brew install homebrew/science/vips

binary symlink is /usr/local/bin/vips

Install VipsScaler extension

• Install VIPS (see above)
• Téléchargez et placez le(s) fichier(s) dans un répertoire appelé VipsScaler dans votre dossier extensions/.
• Ajoutez le code suivant à la fin de votre fichier LocalSettings.php  :

  wfLoadExtension( 'VipsScaler' );
  

• Navigate to Special:VipsTest to verify it is working and see the difference in output quality.
•  Fait – Accédez à Special:Version sur votre wiki pour vérifier que l'extension a bien été installée.

Configuration

$wgVipsCommand

path to the vips command (default: vips).

$wgVipsOptions

Options and conditions for images to be scaled with this scaler. Set to an array of arrays. The inner array contains a condition array, which contains a list of conditions that the image should pass for it to be scaled with vips. Conditions are mimeType, minArea, maxArea, minShrinkFactor, maxShrinkFactor. The other items in the array are options. Options available are:

• sharpen - Set to an array with keys 'radius' and 'sigma', which are parameters to gaussian sharpen matrix.
• preconvert - Convert the file to a .v file first, which costs some space, but saves memory on the actual downsize
• bilinear - Use im_resize_linear instead of im_shrink
• convolution - Apply specified convolution matrix
• setcomment - Add an exif comment specifying the source of the file. Requires $wgExiv2Command to be set properly.

$wgVipsOptions = [
  // Sharpen jpeg files which are shrunk more than 1.2
  [
    'conditions' => [
      'mimeType' => 'image/jpeg',
      'minShrinkFactor' => 1.2,
    ],
    'sharpen' => [ 'radius' => 0, 'sigma' => 0.8 ],
  ],
  // Other jpeg files
  [
    'conditions' =>[
      'mimeType' => 'image/jpeg',
    ],
    'sharpen' => false,
    'bilinear' => true,
  ],
  // Do a simple shrink for PNGs
  [
    'conditions' => [
      'mimeType' => 'image/png',
    ],
  ],
];