Pref Image Extension

Choose the “best” image extension depending on image files which are available and on the output format

v1.0. Copyright: © 2022 Christophe Agathon christophe.agathon@gmail.com License: MIT - see LICENSE file for details.

Introduction

As an author I want to produce multiple document format from the same sources using the more appropriate image file available in order to get the “best” result (image quality, document weight, …).

Usage

Formating the document

Simply use normal image insertion synthax that Pandoc can process. You can omit the file extension

![Image 2](media/image2)

Rendering the document

Copy pref-image-extension.lua in your document folder or in your pandoc data directory (details in Pandoc’s manual). Run it on your document with a --luafilter option:

pandoc --luafilter pref-image-extension.lua SOURCE.md -o OUTPUT.pdf

or specify it in a defaults file (details in Pandoc’s manual).

The “best” image file extension will be used :

• html documents :
  • by order of preference : ‘svg’; ‘jpg’; ‘jpeg’; ‘png’
  • if no files are found with one of these extensions, the image file path is kept unchanged.
• latex and pdf documents :
  • by order of preference : ‘pdf’; ‘png’; ‘jpg’; ‘jpeg’
  • if no files are found with one of these extensions, the image file extension is stripped. We rely on LaTeX to choose one if/when an image file will be available.

Limitations

This filter is active only for LaTeX, PDF and HTML output. It does nothing with other output document format.

The working directory where the pandoc command is invoked must be the main document directory in order to process relative image file paths.

Contributing

PRs welcome.