Jekyll PDF thumbnails generator

A Jekyll plugin to generate thumbnails for your PDF files

Usage

1. Add the following to your site's Gemfile:

gem 'jekyll-pdf-thumbnail'

2. Add the following to your site's config file:

plugins:
  - jekyll-pdf-thumbnail

3. Use it in your .md files and liquid templates. Example markdown file:

    ---
    title: Homepage
    layout: null
    pdf_file: /assets/sample_1.pdf
    ---
    # {{ page.title }}

    {% assign other_pdf = 'sample_2.pdf' %}

    - This is a link to [{{page.pdf_file}}]({{page.pdf_file | absolute_url}})
    - This is a preview of ![sample_1.pdf]({{ page.pdf_file| pdf_thumbnail }})
    - This is a link to [sample_2.pdf]({{other_pdf | absolute_url }})
    - This is a preview of ![sample_2.pdf]({{ other_pdf | pdf_thumbnail }})
    - 50% resize: {{page.pdf_file | pdf_thumbnail: resize:'50%' }}
    - 25% resize: {{page.pdf_file | pdf_thumbnail: resize:'25%' }}
    - 25% resize, 50% quality: {{page.pdf_file | pdf_thumbnail: resize:'25%', quality:'50'}}

• The format of the resize parameter is the image geometry as defined in the ImageMagick manual.
• The format of the quality parameter is a number between 1 and 100 as defined in the Image Magick manual. Currently, only png thumbnails are supported. According to the manual:

  ... the quality value sets the zlib compression level (quality / 10) and filter-type (quality % 10). The default PNG "quality" is 75, which means compression level 7 with adaptive PNG filtering, unless the image has a color map, in which case it means compression level 7 with no PNG filtering.

Developing this extension

• Setup: Clone the extension and execute bundle install to install the dependencies
• Run tests: bundle exec rspec
• Releasing a new version
  • Update jekyll-pdf-thumbnail.gemspec with new version and metadata.
  • Commit your changes.
  • Create a new git tag: git tag -a vx.y.z -m "Version x.y.z"
  • Push all the changes to github: git push origin && git push origin --tags
  • Build the Gem: gem build
  • Upload the new gem: gem push jekyll-pdf-thumbnail-x.y.z.gem