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Is the 4th Yellow Pixel of Sharp Quattron Hype?
Nom du Keyboard writes "Sharp Aquos brand televisions are making a big deal about their Quattron technology of adding a 4th yellow pixel to their RGB sets. While you can read a glowing review of it here, the engineer in me is skeptical because of how all the source material for this set is produced in 3-color RGB. I also know how just making a picture brighter and saturating the colors a bit can make it more appealing to many viewers over a more accurate rendition – so much for side-by-side comparisons. And I laugh at how you are supposed to see the advantages of 4-color technology in ads on your 3-color sets at home as you watch their commercials. It sounds more like hype to extract a higher profit margin than the next great advance in home television. So is it real?"
i'd be much more interested if it was a colour that RGB couldn't produce.
To get truly astonishing pictures, they should add a black pixel, to improve contrast.
It strikes me that a better use of a fourth colour pixel would be to represent all those greens the RGB colour space doesn't actually represent.
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It's like the "120 hz lcd display" stuff. The dvd they use to show you the difference in-store is bogus. If you want REALLY sharp, you'd buy a 600hz plasma. The whole screen changes from one image to the next in 1/600 of a second, with no interpolation (and interpolation algorithms are just "best guesses", so they're no better than an upscaler would be).
And I laugh at how you are supposed to see the advantages of 4-color technology in ads on your 3-color sets at home as you watch their commercials.
Well, I'm not sure if you're correct to laugh at this or not. But all televisions are approximations of something analogue that was captured and in that capturing process, some information was lost. To illustrate, entertain a scenario where I have N standard definition television sets that are displaying footage from standard definition video cameras. I daisy chain them together (each camera directed at the last screen) to record something. As I move from the 0th screen to the Nth screen, I will begin to see degradation as more information is lost and randomness comes into play. The same can be done with HD but since HD captures more information, it can safely be assumed that the sampling and resampling will retain more of the original image.
If you played the Nth HD screen next to the Nth SD screen and piped that through an SD television, you'd still be able to see some difference (for reasonable non-astronomical numbers of N) even though you went through yet another SD television in the end.
I don't know what the fourth color is supposed to buy, I'm unfamiliar with this technology. But the side by side comparison through an SD or HD TV might still be able to demonstrate that the fourth color adds some meaningful information to the image that -- when resampled to be viewed on your device -- suffers less information loss than the three color implementation. Thus successfully demonstrating some superiority. Not showing you precisely what the final product is supposed to be like but instead give you relativity in signal loss and noise.
I also know how just making a picture brighter and saturating the colors a bit can make it more appealing to many viewers over a more accurate rendition
Well, I know that there is a huge photography following that is totally enamored with HDR photography and to many people it makes the images come to life ... I think it's overdone (like autotuning in modern music) but it definitely has a place. Perhaps similarly four color displays hope to widen the dynamic range they can display? I wish I could give you better answers about four color displays but this is the first I've heard of them. Perhaps your questions to a large engineer base are the most effective kind of marketing?
My work here is dung.
Puny human eyeballs only have three kinds of cones, one that peaks in response to red, one to green, and one to blue. While our superior alien overlords may be pleased with this new technology, physiologically, you can't tell the difference.
Adding an extra phosphor can extend your gamut, increase your dynamic range within your gamut, or give you finer quantization within the gamut, or some combination of all three. The fact that your source material is provided as three quantities (YCbCr, not RGB) doesn't mean four phoshors won't help.
Doesn't mean it will, either.
Time to wait for all the /.ers who don't actually understand colour theory pipe up with comments of how 3 colors is more than enough for everything simply because it was a design choice that was made several decades ago.
How do you decide which pixel to sacrifice for the colour gambit?
Blar.
Is that supposed to be some kind of joke?
http://www.rootstrikers.org/
Representing yellow with a mix of green and red is already a hack. What's wrong with software determining that the color of a pixel is yellow and actually lighting up a yellow light?
Maybe a yellow light looks more convincing than a red and green light right next to each other. I'd want to see for myself before making blanket judgments.
At first blush it appears to be hype but I am trying to keep an open mind because of something that happened to me when I saw my first HD TV picture. I was of the opinion that HD couldn't be that much better than SD. Shortly after I saw my first HD images I was ready to admit that I was wrong. From the moment I laid eyes on HD I knew there was a whole new world out there! I am now a certifiable HD snob. I don't know what I did before but I do know I watched less TV.
I haven't seen one of the new TVs yet to day I think it makes a difference or not. I will know, and probably rather quickly when I see it if I believe it or not. The first place I will look is at white/black interfaces. That should tell me a lot.
I really do hope it is hype. I think the 47" TV is a little too big to be moved into the bedroom.
First - if it's working correctly you shouldn't even notice it. Second, Sanyo has been doing this for a few years in their projectors. The yellow panel helps warm up the color range and keep your tv's backlight from getting too far in the blue range. Read Sanyo's whitepaper: http://us.sanyo.com/shared/docs/QuaDrive_SANYO_WhitePaper08.pdf Alternatively try searching for Sanyo Quadrive
First, check out http://en.wikipedia.org/wiki/Gamut for reference. The sample gamut picture in the top right shows a typical CRT--lets assume for the sake of argument that LCDs are similar.
If you add a yellow LED to that it just isn't going to add much. The yellow part of the spectrum is already fairly well represented.
*But* if they also change the hue of the green LED toward the blue spectrum then it has a good chance of really opening up the gamut.
The people saying RGB is enough don't understand chromaticity--go look for gamut plots of your favorite output devices and see how little of the full spectrum of colors they can actually reproduce. Printers are especially embarrassing. Your eyes can really see a whole lot of color detail.
There. Now go play some cool javascript games!
Right?
/obscure? Hopefully not for the /. crowd...
Digital images are displayed in RGB, yes.
But colors are printed in CMYK (Cyan Magenta Yellow Black), and you'll notice that the best photo inkjet printers have more than just those four color cartridges. They often have the four plus "photo cyan", "photo magenta", etc. and it does make a huge difference.
As you know, some colors cannot be accurately expressed in CMYK, nor can some in RGB (even though theoretically any color is possible, but theory is not reality in this case).
While the extra color may or may not make a big difference, there is at least precedent indicating that the idea is sound.
Computer Science is no more about computers than astronomy is about telescopes. --E. W. Dijkstra
The red one, just like on Star Trek.
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
"And I laugh at how you are supposed to see the advantages of 4-color technology in ads on your 3-color sets at home as you watch their commercials."
But the script of the commercial is written almost entirely with deference to that fact.
The estimable Mr. Takei tells you, while you're no doubt ogling his adam's apple instead of listening, that he can't actually show you the difference itself, but, "I can show you this," wherupon he looks at the screen and gives his review in a single, somewhat gaudily overacted word.
I'm not sure how anyone misses that, since his behavior is utterly bizarre without the concept of telling-not-showing being in play.
http://regmedia.co.uk/2010/05/07/quattron_4.jpg That just about sums up the entire article.
If you look at the color spectrum and its frequencies, you will notice the following:
red -- 610 to 760 nm
gap - 590 to 620 nm
green -- 500 to 570 nm
blue -- 450 to 500 nm
Now I couldn't find any actual explanation on the net for why Yellow would make a better picture. But if you look at the frequencies above, you will notice that adding yellow DOES do something. It reduces the gap between Red and Green by half; Yellow is in that gap, and comprises the frequencies from 570 to 590.
By this theory, maybe adding Orange (590 to 610 nm) would make an even more realistic picture?
Now you're just hatin'. They say right in the ad, how you can't see the difference because you're watching a regular TV, but you can see "THIS" and the screen turns 90 degrees so you can see how thin it is (and the asian dude goes 'whhhooooww'). Anyways, I saw one in a BestBuy yesterday, and all I can say is that it looked very, very nice. I was impressed with the overall color (yeah, it was mostly just saturation, but Avatar was playing so it worked) as well as motion smoothness.
The tone of this article isn't like the summary states. TFA doesn't portray the TV as some magical device; because the article is actually somewhat critical of the TV.
I think the thing that a lot of us don't realize, because we spend so much time looking at TV and computer screens, is that colored light isn't really a combination of red, green, and blue. The reality is that light gets its color from its wavelength; and we can get a very close approximation by combining light we perceive as red, green, and blue.
The question is, can we get a more accurate picture by using light that's closer to the original wavelength? Clearly, the information isn't lost, as the original wavelength can be inferred by digitally processing the original RGB levels.
Something to consider is that the original NTSC (American Color) TV standards didn't just include Red, Green, and Blue, but also included Yellow and Orange. These parts were essentially deprecated, but the concept of TVs displaying yellow isn't new.
No, I will not work for your startup
Quick terminology: Spectral color- Pure, single wavelength color, like a laser. Composite color- A combination of many spectral colors of different intensity.
To truly reproduce a color, each pixel should be able to not only make one spectral color, but a combination of all of them.
This would be very expensive, and fortunately, our eye have sensors only for Red 580 nm, Green 540nm, and Blue 440 nm (RGB), if we exclude the low light rods. We can therefore get away with RGB screens. There are slight errors. For example, assume each R-G-B pixel emits light matching the eyes R-G-B sensors peak sensitivity. Now, we can reproduce any light stimulation by exiting a linear combination of the three emitters. The eye however is sensitive from 380 nm to 740 nm, and can obviously not create the stimulation for neither 400 nm light, nor 700 nm, as your linear combination of only positive values will not cover these spectral colors (outside the gamut of the display). Take a picture of a prism spectrum or rainbow, and compare the original with what you see on the monitor, and you can see this.
So bottom line, RGB covers almost all colors, but adding emitters allows linear combination to cover more of the possible stimulation, but a high cost for little value. It is primarily the near UV purplish blue below 440 nm and the warm reds near IR that can not be reproduced.
don't cut it off www.mgmbill.org
A lot of TV sets that use local dimming have a big problem showing starfields. The average color in a starfield is pretty dark, so the LED goes dim and not bright enough to show the stars. It really takes the punch out of Star Wars Special^n Edition if you can't see the stars.
Why not just go to the store and look for yourself?
With RGB pixels on an LCD, yellow is shown by allowing light to pass through neighboring red and green subpixels. For the red subpixel, blue and green are filtered out. For the green subpixel, blue and red are filtered out. Then the eye fuses the neighboring pixels together to get yellow from two sources that have already filtered out much of the spectrum. But with a single yellow subpixel, only blue light is filtered out and more light reaches the viewer. I'm sure the effect is to make certain colors more vivid.
Additionally, the use of these yellow subpixels is also to somewhat increase the effective resolution.
In terms of color theory, nothing stops is potentially being real. If you expect to hook this up to some random source and get an improvement, though ... good luck. It's not going to happen. With an appropriate 10-bit or 12-bit wide-gamut source, though, it's certainly capable of better results.
The input may be 3-color (RGB), but if it's defined with a wide-gamut space like Adobe RGB, possibly with up to 16 bits of precision per colour channel, then it can represent a huge range of colours. It can do this by defining near-"perfect" primary colours and assuming perfect control over blending of those primaries.
A regular TV, though also an RGB device, has a very different gamut. That's largely because the primary colours the TV uses aren't as bright/saturated or as "perfect" as those in the Adobe RGB space, but it also can't blend its colours as well. Most likely it only uses 8 bits per colour channel, so it has a much more limited range of graduations, further forcing the colour space to be narrowed to avoid banding due to imprecision.
The regular TV must "scale" a wide-gamut input signal in a colour space like Adobe RGB to display it on its own more limited panel. It can do this by "chopping off" extreme colours, by scaling the whole lot evenly, or several other methods that're out of scope here. Point is, that they're both RGB devices, but they don't share the same colour space and must convert colours.
So, if the yellow pixel (another primary) expands the gamut of this new TV, then yes, even though it too only takes an RGB signal, it's in theory better, because it can convert a wide-gamut RGB input to its own RGBY space for display with better fidelity than a TV with the same RGB primaries but no Y channel colour achieve.
Another device might still be plain RGB, but for each of the red green and blue primaries it might have much better (closer to "perfectly red" etc) colour. This device might have an overall wider gamut (ie better range of colours) than the RGBY device, though it's likely that the RGBY device's gamut would still be capable of better yellows. (If you're struggling to figure out what I mean, google for "CIE diagram RGB CMYK" to get a feel for it).
Attaining better results through adding a channel and/or having better R,G,B primaries presumes properly colour-managed inputs to gain any benefit, though. In reality, video colour management is in a pathetic and dire state - inputs can be in any number of different colour spaces, there's no real device-to-device negotiation of colour spaces, and it's generally a mess. If you feed a "regular" narrow gamut source through to a TV that's expecting a wide gamut signal, you'll get a vile array of over-saturated over-bright disgusting colour, so this is important. Since this device would rely on wide-gamut RGB input to have any advantage, it'll need a 10-bit or 12-bit HDMI or DisplayPort input with a source that's capable of providing a wider gamut signal (say, BluRay) and is set up to actually do so rather than "scaling" the output video gamut to the expections of most devices.
The fact that most inputs only support 8 bits per channel (and thus aren't very useful for wide-gamut signals because they'll get banding/striping in smooth tones) really doesn't help.
There have been a number of studies recently reporting that at least some women have four types of cones (the "colour sensors") in their eyes. i.e. they can see four primary colours. The trait is called tetrachromacy.
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Color on RGB monitors currently is a fine match for standard broadcast/HDTV/Blu Ray gamut, and LCD monitors are plenty bright, this really doesn't solve a problem anyone was actually having.
Sharp has among the worse LCD tech(IMO) with weak (grey) blacks and a lot of viewing angle shift.
The first reviews that I read, say these problems persist, so Sharp didn't work on real (hard) they have with their technology. Instead they decided to tackle something they can use as a marketing differentiator to impress the rubes.