probablycorey/mini_magick — pull request #75 by loe (2012-02-16 22:17:13+00:00)
Title: Only convert one page unless explicitly asked to convert them all

When converting between formats convert only the first page, if you would like to convert all the pages use 'nil' or 'false' as your page.

In 99% of cases people use this to generate thumbnails, which typically means the first page. It is a huge waste of resources to convert all the pages, then choose the first one. Adding [0] to the path causes ImageMagick to convert only the first page.

If you are knowingly converting between animated formats you can pass nil or false as your page and all pages will be copied.