GIMP¶
Guide to using Gimp (Gnu Image Manipulation Program)
Overview¶
For starters - if you pronounce "Gif" with a soft G, you're wrong. Societal trends dictate culture, and modern culture says they are pronounced like gorilla, gang, grill, and glasses. If you pronounce "Gif" with a soft G like Jif (the peanut butter), giant, or gym, you are strictly prohibited from using this guide.
Jk who's going to stop you.
Cropping Gifs¶
The unfortunate thing is that this guide is written for a non-default software program. Depending upon your employer, you may or may not be allowed to install this on your work computer. I have installed GIMP on my home desktop to write this guide.
Import your media into GIMP
Select the crop button
Drag a square over the image you want to crop. You can fix the dimensions and stretch the crop tool to the edges of the image. Make sure you crop to a square size (height should match width) in order to get the best quality import into slack
Drag the image to roughly center it over the subject
Press the keyboard combination SHIFT+C to crop the image
Now go to export the image
Cancel or Crop
A popup may appear: "The image you are trying to export as a GIF contains layers which extend beyond the actual borders of the image. The GIF file format does not allow this. You may choose whether to crop all of the layers to the image borders, or cancel this export."
Select the "Crop" option
Crop Options
In the next popup, be sure to check the "As animation" box or your Gif will no longer be a Gif
You should now have a cropped Gif!
File too big warning
If you receive errors about the file being too big, you may need to compress the image, resize it, or remove frames. I personally like Ezgif for small edits. Here's some results for "slack gif max size"