I wonder how much of a role wetting/capillary effects play in this? The liquid interface will distort as it approaches the object, and will try to meet at a certain contact angle (based on surface tensions etc). Correcting for this might help improve the resolution of the scans?
This is speculation, but perhaps there's a game-theory issue here. If IEEE loses money by people pirating (and you can apply the usual counter-arguments about whether the pirateer would have gone on to purchase it anyway) rather than paying then publishing costs increase to cover that loss, and therefore hurting the authors who must cover that increase in future if they want to publish in the journal again.
A better situation is where the preprint or open access version is available.
Interestingly, these look very similar in design to so-called bacterial ratchets (see Fig 7 of [1]) which allow swimming bacteria to be sorted by size or swimming speed etc. People have even used these ideas to create tiny bacteria-powered motors [2].
I've tried a variety of RSS readers recently for keeping track of academic publications (arxiv and journal feeds etc). I've settled on inoreader [1] as this: (i) includes a search feature in the free tier, (ii) has keyword highlighting (useful for trawling through long lists of papers), (iii) has a reliable Android app.
It's interestingly that the Gibbs phenomenon appears visually as a whiplash effect. You can see how it would only get worse as higher order terms are included.
http://www.geograph.org.uk/photo/81429