They don't do any processing except maybe the subtractive blend of putting ink over other ink. Presses are pipelines so you get some pipeline type similarities and sure they deal with images but a meh. A press is more similar to a monitor than a GPU, I would think.
Printing presses are interesting machines, but they are not at all related to GPUs. Although newer ones probably have cameras looking at what's coming out and a GPU processing the imagery. Presses used to have a huge number of manual adjustments to ink flow for how much of each color is being used for each column. That's been automated for years, because you went through a lot of paper during manual tuning.
And yes, there are presses that do plate changes on the fly.[1] For "those profitable short-run jobs".
Printing is a dying industry, though. Printing huge amounts of paper to be thrown away the next day is over.
It still takes a surprising amount of “make ready” paper to get to steady-state ink consumption even with automated color management. For short run jobs, this can easily be 100+ sheets for a net 250-sheet job.
Digital presses are not subject to the same degree, so the job cost crossover has been steadily climbing over the years. (The point are which a job is equally cheap to do digitally vs analog litho.)
That video at the end is pretty amazing. In the video, they mention that the press runs at 15 m/s (54 km/h, 33.55 mph) and that it operates 24 hours a day.
Doing the math, this machine ingests over 800 linear miles of paper per day. Crazy!
It's not GPU, it's called RIP - Raster Image Processor. And yes, one of the benefits of print is, that it is already pre-rendered. Waiting for a PDF reader/browser to show a complex vector image is just annoying.
The article is interesting, but the title is clickbait in that he never really tries to make the argument claimed in the title. Instead, he looks at both GPUs and printing presses as generic image formation devices and compares them on those terms.
Paper mills and perhaps these machines too could be Turing complete, and very similar to Turing's original machine with infinite tape, if they perform some kind of online process control.
