Thumbnail issue for BW PDFs

[gwiedeman]

Hyrax currently makes bad thumbnail images for black and white PDFs. Color images and PDFs seem like they work fine. They look like:

This is because we are using an older version of ImageMagick. Apparently updating to ImageMagick 7 will fix this, but that is not supported on our current OS. We should make sure this is addressed when we get around to Dockerizing. Once this is addressed it would be challenging to re-generate all thumbnails, as in most cases the files only live in Fedora and (from my understanding) are not directly accessible to Hyrax on disk.

There is a closed Hyrax ticket for this.