I've been collecting these and at first I did not like them at all. But given the age of the works and how no one's going to pay to commission original artwork for such things, I've started to warm up to them over the last year or two. Especially since they're better than many of the generic retail images (Gollancz is a yellow background with the title on it, woohoo).
But then, I started coming across some of them where they choose to use old original covers instead. Some of these are beautiful, the book they're scanning from is pristine, and the scan work's solidly professional.
However, some of the books whose covers they scan look like they were dug up out of a landfill (and probably weren't attractive to begin with). Other times, they use a title page as the cover image. And, inexplicably today, I found two in a row where they were using a scan of the spine, which makes no sense whatsoever. (Might have something to do with when they were released, some really old circa 2001 retail ebooks I've seen had spine images too.)
I'd like very much to run some script, and have it spit out a Gutenberg-style geometric cover image that I could replace those with. I'm assuming they have some software that generates those procedurally, and it's not some guy who painstakingly drawing out the little blue triangles on a green background in MS Paint. But I've not been able to find anything like that, or hints of how they do it. There was nothing on their github page last I checked.
Does anyone know how these are done?