Forgive me if I'm misremembering details, but I think the way color e-ink displays work is they have the black/white "ink" capsules that are pushed up/down by magnetic charges, just like a regular black/white e-ink display, except for in the colored ones, each "pixel" also has a red or green or blue color filter over it (one of each in a cluster). But that means the pixels per inch drops because now 3 black/white "pixels" have to work together to be one single color "pixel"
I'm not really sure how they measure resolution with this, that could still just be a mistake. But I do know e-ink displays sacrifice resolution for that colour with current technology.
So, assuming that’s what it is, subpixel resolution is now being advertised as the “true” resolution? Because when I buy a 1080p display, I’m expecting 1920x1080 addressable pixels. Whether that’s implemented as 3840x2160 (2x2 subpixel) or 5760x1080 (3x1 subpixel) is not my concern. And if I bought a display advertised as 3840x2160, and my computer told me it was 1920x1080 (because it’s a 2x2 subpixel layout), I’d be upset.
In Apple ][ hires graphics, the 280 pixel-wide display area was really 140 pixels with the extra resolution coming from sub-addressing the RGB pixels on the display. On a black and white display you got the full 280 pixels but in color you would get weird color fringing happening. Even more fun was that one byte of memory was mapped to 7 "pixels" with the high bit indicating how the RGB sub-pixels would be split into the left and right halves of the pixel. Technologically it was rather cool, although it was a challenge to program against.
Wow, I never understood until reading this comment that this is why Apple II graphics often had that fringing effect. Those visual artifacts I remember from The Oregon Trail finally make sense.
Bad precedent, to be honest... Pentile was infamous for its inferior image quality on things like text and fine lineart.
It reminds me of the LCDs on digital cameras, some of which use the same trick to reduce costs --- natural photos don't look any different, which is why it gets a pass, but text has a noticeable graininess to it as a result.
They can! Not frequently, I'll grant. Once I was using Lightroom and was very confused by a pixelated looking edge of a yellow flower against a blue sky, the edge of which moved diagonally across the pixels. Eventually I realized it was the mosaicing! I actually ended up switching to RawTherapee for that picture, the AMaZE demosaicing algorithm handled it much better in that particular case. Lightroom in the last few years added a high quality demosaicing mode that you can selectively enable, and it handles the picture correctly. It's pretty slow though.
In any case, reporting resolution using the single-color "pixels" is probably more justified for an image sensor (with its array of square light detecting sensors), than it is for an LCD screen, which is usually a square array of non-square sub-pixels.
Pentile is more complicated, since for most of them the advertised number of pixels matches the number of green elements, but not the number of red or blue elements.
At least one HN story in the last month was an eInk type product, either them or a competitor, able to position the tiny cells into more than one pair of modes, the current ones is up or down this one had some colour space like rgb as well. So it wasn't 1/3 the pixel density for a colour pixel.
I'm not really sure how they measure resolution with this, that could still just be a mistake. But I do know e-ink displays sacrifice resolution for that colour with current technology.