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A Billion-Color Display
The Future of Things covered the introduction last month of HP's DreamColor display, with 30 bits/pixel, developed in conjunction with DreamWorks Animation. The display is aimed at the video production, animation, and graphic arts industries. HP promises blacker blacks and whiter whites — though TFoT quotes one source who notes that if they deliver this, it will be due to the back-lighting and not to the number of bits/pixel. No word on the size of the displays that will actually be delivered, or on the price.
And yet that 24bpp can't reproduce the full range of colors that can be printed on a piece of paper. And the ink on that piece of paper can't reproduce the full range of colors visible to the naked eye. Yes, there's room for a whole lot of improvement. That's not to discount the progress we've already made (24bpp is pretty impressive), but there's still a long way to go.
This guy's the limit!
how am I supposed to see how good this display is if they don't show me a picture of it?
Most new displays have a resolution of 96dpi, whereas low-end printers can easily pull off 300dpi. Same goes for color-depth. Black and White screen images at 8 bits/pixel simply cant match the range of black&white print & film.
When you think about it, techniques such as anti-aliasing are really just hacks to work around the limitations of today's monitors. If monitors could pull off 300dpi, you wouldn't need anti-aliasing.
I know you're jesting, but our eyes are definitely capable of appreciating 30 bits, and many megapixels as well. Our eyes don't work like cameras; we're excellent at discriminating fine differences within the area we're looking at. We might not be able to tell #cc1111 from #cd1111 in isolation, but if they're right next to each other we can see that difference and more.
(On a similar note, in the center of our visual field, we can discriminate physical positions with much greater accuracy than the receptor density would lead one to believe, because our analog receptors are capable of discerning fine differences by working with their neighboring receptors. So anybody who says "X resolution is higher than humans can see" is talking out of his ass. You can tell when they know what they're talking about when they say something like "at this resolution, most humans will only be able to perceive a 1-pixel difference 60% of the time" or something which sounds a lot more like signal theory than somebody comparing one arbitrary number to another arbitrary number.)
Just as in audio where quantizing becomes a problem only in very low level passages, fine greyscale, especially in the blackest image areas, will benefit from more bits/pixel.
For example, an ordinary CD (16 bits) can sound rather gritty on quiet recordings such as the low level passages of classical music. That's because you're probably only using two or three bits of sample depth down there. To combat the issue, 24 bit audio will elevate the sample depth everywhere but will show itself best at low levels. Dither (essentially noise) is used to randomize and mask the problem, but that's a cheat.
In video, fine greyscale performance comes from higher bit depth per pixel and is visible throughout the entire luminance range. The issue shows itself on flat (un-textured) areas with minute lighting changes across the surface, like a softly lit painted wall. You'll see annular rings on the surface as the bit values step through their range. Again, dither may be used to randomize the quantized transitions.
24 bit video is really 8 bits per primary color - so it's not that good to start with. In professional application, it's not unusual to work with 10 bit [per channel] or even up to 16 bit[per channel] images, mostly to be more friendly to post production.
Fortunately, analog humans are fairly blind to minute color changes. Unfortunately, our system of digital video happily shows you everything wrong with it.
Most of the stuff on
Modern monitors use an additive method of color blending, while printers (by their very nature) must use subtractive blending.
The range of colors that can be reproduced by a 24-bit RGB device is always going to be different from the range of colors that a 24-bit CMY device can reproduce.
By the same note, a 24-bit RGB display can produce colors that the CMY printer cannot.
One color space isn't bigger than the other; they're simply different. Once you increase the bit-depth far enough to encompass the full spectrum of visible light for both color spaces, the distinction can finally be dropped.
-- If you try to fail and succeed, which have you done? - Uli's moose
They're absolutely right that CMYK does not encompass RGB. They overlap for a large part, and don't overlap in small areas (with one larger area in the deep vivid cyans).
However, a larger bitdepth doesn't do anything for color space. It simply determines the granularity of that color space. If with 16 bit you get 65,536 individual colors within the RGB gamut (with slightly higher granularity in the green channel, typically), and with 24bit you get 16,777,216 individual possible colors within the RGB gamut, then with 30 bit (10 bit per channel; it's not new, really), you get 1,073,741,824 individual possible colors... but still within the RGB gamut (of the device at hand).
An HDR display (either by using a very bright backlight or more localized LED backlights control, etc.) also doesn't change the gamut of that device - it simply allows for much brighter values of them.
Now, if they were to make an LCD panel that aside from the R,G,B pixel elements also had C M Y pixel elements, then you most certainly could increase the gamut. It would also be much more difficult to switch to than a simple bitdepth change.
To see billions of colors at the same time one only needs LSD technology...
how long until