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Originally Posted by NiLuJe
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Thanks for the link, and it may indeed help people to understand dithering in a more visual manner.
Dither methods other than ordered dither can look better for static images, but my experimentation shows that for eink displays, it is important to not change pixels too often, which causes temporal aliasing with the eink drivers, with artifacts that vary between kindle models. The result as mentioned previously is a fading trail that pulsates and can be very annoying for movies or video games. However it does look interesting when that effect is used for artistic purposes, like in one of the demo effects used in my newtrix demo.
As it turns out, the ordered dither matrix remains anchored to the display, assuring that pixels only change when they really must.
However, for displays that do not have such requirements, such as LCD or OLED, adding a temporal component to the dither (pixels not anchored to screen coordinates) can improve the image. The non-anchored sparkle gets averaged out by the eye, and in fact most modern LCD displays actually do some degree of temporal dither to achieve more effective colors than the hardware could do otherwise.
But we are working with eink here, where an anchored dither has positive perceptual significance in how it interacts with the eink display hardware and device drivers, hence my choice of dither method.
EDIT: Ordered dither is also known as "Bayer dither", as it is called in the linked page above (which also shows that it provides best compression, due to fewer pixels changing between sequential video frames, besides being more "eink compatible" due to less "pulsating" temporal artifacts).