title: Best approach to create thumbnails?
body: <p>Im working on a template for a website that has already more than 50,000 articles and images assigned to every article.
  Before now the article image was visible only inside every article, but now I would like to use thumbnails.
  I don't have access to modify the upload image form, so the solution should be something like virtual thumbs created from the original images...
  What will be the best approach in this case?</p>