High RAM memory consume previewing gif

Loading a gif inside the Administration makes very slow the computer: First time i see this performance inside a Docker container, and i reviewed it in local environment and i got the same result.

Issue Summary

Each time that we upload animated gif and after we go to preview it(after creating the new image or since image section), the computer’s memory becomes full and the SO have to kill django server for get back normally.

[30/Apr/2017 10:41:49] "GET /admin/tag-autocomplete/?term=soluci%C3%B3n HTTP/1.1" 200 2
[30/Apr/2017 10:41:53] "POST /admin/images/multiple/2/ HTTP/1.1" 200 32
[30/Apr/2017 10:42:06] "GET /admin/images/ HTTP/1.1" 200 4071
[30/Apr/2017 10:42:06] "GET /media/images/problem.max-165x165.gif HTTP/1.1" 200 522647
[30/Apr/2017 10:42:06] "GET /static/wagtailadmin/images/transparency.svg HTTP/1.1" 304 0
[1]    13384 killed     ./manage.py runserver

Steps to Reproduce

1. Create a new image
2. Full all fields
3. Load a gif image
4. Save.

Or:

1. Open and page or image in the admin

Technical details

• Python version: 3.6.1.
• Django version: 1.10.7
• Wagtail version: Hover over the Wagtail bird in the admin, or look in the Settings menu, look in your requirements.txt, or run 1.9.
• Browser version: Chrome
• Sistema operativo: x86_64 Linux 4.10.11-1-ARCH
• Wand version: 0.4.4
• Pillow version: 4.1.1
• Imagemagick version: 6.9.8.4-2

[BertrandBordage]

That’s great! We’ll finally have meme websites in Wagtail!

[kaedroho]

There’s a couple of fixes to this upcoming:

• https://github.com/wagtail/wagtail/pull/5227 Which will limit the total number of pixels in animated GIFs to 100 million (this is adjustable)
• https://github.com/wagtail/Willow/pull/76 Which adds support for resizing animated GIFs using Pillow, which is generally more efficient on memory usage than Wand