Large diffs from font rendering

Hello, thanks for the module.

I know that you are aware of the issues but I'm trying to understand what I can do about them. In particular I see a large difference between two images that are similar, with some apparent minor difference in the font causing the failure.

I've inspected the generated images and they are the same (physical) size, dpi, etc.

I see some discussion (e.g. https://github.com/astropy/astropy/pull/7150) about maybe just choosing the font appropriately to minimize this. Is that the current recommended solution?

I also gave the perceptual hash (#21) a go and it does generate identical hashes for the two images, which is nice. However I haven't yet had time to look into that more to really understand what it is doing so don't necessarily want to rely on it.

Baseline:

Generated. This is missing the title as `remove_text=True` is enabled (#68 would be relevant here):

Diff:

This is coming from https://github.com/panoptes/POCS/pull/735

(Note that even getting these images out of travis was a huge pain as travis doesn't allow artifacts to be uploaded on pull-requests...but that's a different issue).

Start by reproducing the image comparison from POCS pull request 735 and review the referenced discussion in astropy pull request 7150. Compare the font-rendering differences with the perceptual-hash approach from issue 21; the issue is resolved when a concrete, documented recommendation or defined fix exists.

Written by the indexing model from the issue text.