A Jekyll plugin to generate image thumbnails with specified width.
Add the following to your Gemfile:
gem 'jekyll-thumbnail-img'
The plugin provides a Liquid filter thumbnail_img as follows:
{% thumbnail_img <path to image> <width in pixels> %}
This can be used in img tags as follows:
<img src="{% thumbnail_img path/to/image.jpg 500 %}">
This will generate a thumbnail of width 500px with the same aspect ratio as the original image in the directory path/to/thumbnails with the name image_500w.jpg which will be used as the src attribute of the img tag.
Alternatively, Jekyll variables can be used as follows:
<img src="{% thumbnail_img page.image_path 500 %}">