Creates an empty gap if a long image is generated

[Coletterbox]

If the image is too long, a large, white gap under the tube lines is created. This is pretty minor, but it could potentially be an easy fix if you filter out images that are longer vertically than they are horizontally.

[georgiamshaw]

Here's an example.

[georgiamshaw]

Maybe there's a way to filter out images with a height over a certain length?