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.

Comments

Come back after you've turned off anti-aliasing.

[nobodyman]

Is it really possible to improve screens further, in a way that's visible to the naked eye?

I think so. As a quick example of why I think this, temporarily turn off anti-aliasing in your OS. The characters on the screen should look pretty crappy relative to a book or an illustration. So, I think we have a ways to go. I think the same is true for color depth, it's just hard to recognize it because we have gotten used to 8 bits/pixel.

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.

Re:To what end?

[Divebus]

Is it really possible to improve screens further, in a way that's visible to the naked eye?

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.

Re:To what end?

[moosesocks]

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.

Mod parent (or his sibling) up... however,...

[Animaether]

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.

Re:Oh no, not again

[50000BTU_barbecue]

Again, I think you are wrong. There was a big stir just a few months ago about Apple displays being 18 bit. I think most LCD panels sold for PCs are still 18 bit panels, which is why you'll find it incredibly hard to get a simple, blunt "24 bits per pixel" mentioned on the box, or the company's website. But you'll get a gigantic "2ms response" sticker on the box. At best, you'll get something like "16 million colors" which means 18 bit, and 16.7 million colors when it's a true 24 bpp display.

Again, read this.

As for the 1600, the trade-off you have for a true 24 bpp display is narrower viewing angle and slower response time, this is due to the physics of the crystals. Check out the National Semi page for lots of info on what exactly a liquid crystal is, what the different types are and how they're driven, and lots of amusing info on the guts of LCD panels.

But for the dithering, it's sort of like buying CDs with 16 bit samples, but CD players only having 12 bit DACs but it not being written anywhere. But then, if no one can tell, why choose 16 bits in the first place? This reminds me of the waning days of Minidisc when suddenly everyone here became a very critical, golden-eared audiophile and could tell the difference between a CD and MD, but the same people turn around to their 18 bit displays, can't tell the difference, and go on thinking they are 24 bits.

Life on this planet never ceases to amaze and befuddle me.

Re:Come back after you've turned off anti-aliasing

[phasm42]

The ClearType used by Windows really gets me. Yes, it does make the shapes smother, but what it does is turn the edges into rainbows.

This may be due to your monitor not being specified correctly. IIRC, there are two main types of LCD panels: RGB and BGR (different color orders), and in order for ClearType to work correctly, it has to know which one you're using. I've noticed if someone does a non-lossy screen capture of some ClearType text on a computer set up for the opposite sub-pixel color order than what I use, the text looks crappy and has that rainbow effect.