How to get direct link of images on Imgur

I can't actually find it documented anywhere, but I uploaded an image and played with the "More Sizes" list:

Original

http://i.stack.imgur.com/YdJZt.jpg

I haven't included the image inline, because StackExchange would automatically scale it down. To view the original at its full size, click the link.

Large thumbnail

http://i.stack.imgur.com/YdJZtl.jpg (added an l after the image ID)

Small square

http://i.stack.imgur.com/YdJZts.jpg (added an s after the image ID)

It doesn't always handle transparency well, but "small square" is probably what you want.

_{Image by digitalART2, licensed under CC-BY-2.0, available here.}

I found out that imgur has an outright ban on the site for some reason. No one knows why.

The workaround is to use the site's https connection, then the images will load. We guess imgur didn't ban https://site.com.