When you upload an image to Craft, the image is automatically “cleansed” using the same basic process that Craft uses to create image transforms. That happens to ensure that there are no malicious scripts hidden in the images, and it’s not something you can disable.
No Current Good Solution
Having liaised directly with Craft Support on this issue, the outcome after a bit of research was that there is not currently any good solution.
Apparently, Imagick is really, really bad at animated GIFs, but there's no other option.
My workaround was to edit the templating for gif images, so a super-simplified version would look ...
For Craft to use it, yes the ImageMagick PHP extension is required because Craft uses PHP's bindings in the library they're using.
Depending on the host's OS, it should be a package manager update away. Any decent host should be able get it working incident free.
Although this issue turned out to be the result of a bug, for the record you can bypass Craft's image processing step by manually uploading an image directly to the assets folder on the server (ie. via FTP rather than Craft) and then selecting "Update Asset Indexes" in Craft's admin panel (under "Settings"). This allowed me to get the problem image up and ...
Is this a one-off image or do you need to use the transform for a bunch of GIFs?
There's no way automated way to tap into transforms currently. (Craft 3 is going to be much better in this respect.)
The other hard part is you're probably going to want to specify what frame of the GIF to use. (Fun fact: years before browsers supported animated gifs, they ...