It would be neat if more people used “hexagonal” (i.e. in an equilateral triangle grid) pixels for capture, processing, display, printing, etc.; with higher and higher resolutions and fast GPUs (so that high-quality resampling can be done on the fly) it should be entirely possible to swap out individual parts of the pipeline without losing quality or performance (at the expense of a bunch of work to implement something nonstandard).

A lot of artifacts are easier to deal with on a hexagon-pixel grid. Halftoning and error-diffusion dithering work really well.

Ooh, interesting thought! I think I might have used a hex image to make a game at some point, but other than that I have little experience with them. Do you think the overall benefits of hexels would make it worth trying to standardize the pipeline?

I'd guess that the need for error diffusion and half-toning might wane in the future. (Not sure about that, but that's what I'd guess.) Are there other benefits you get with hex images?

The big advantages are (a) they’re much more isotropic, (b) there is less effect from grid artifacts (reduced moiré patterns, etc.), (c) they are noticeably more efficient in terms of sampling rate for a given quality of signal. If everything is done on such a grid end-to-end, you get quite noticeably better quality results for just about everything (with the exception of slightly worse results for drawing sharp grid-aligned rectangles). Even swapping in such a grid in one or another part of the pipeline can usually net some advantage.

The downside is that there are a zillion implementations of everything you can imagine w/r/t a square grid, whereas implementations on a triangular grid of hexagonal pixels are fewer and further between, often some crappy matlab code written by a grad student, so you’d maybe need to reimplement, optimize, debug, etc. a whole pile of tools, or even invent some new algorithms for doing stuff that hasn’t been tried on such a grid before.

There have been lots of papers written about the topic, and at least one book. http://www.springer.com/us/book/9781852339142

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It’s similar to the advantages you get from tri-axial fabric: it’s better but requires custom machinery, so in practice is only used for bullet-proof stuff, space suits, and art projects. Hexagonal pixels end up getting used in medical imaging, astronomical imaging, and the like, where pixels are individually expensive.

Here's another great article about hexagonal grids:

http://www.redblobgames.com/grids/hexagons/

It's written with game design in mind, but many of the techniques are useful just the same.

I think Fuji makes some cameras with a hexagonal grid sensor. All our algorithms are based on a square grid though, so it makes it very tough to work with unless you do a conversion.