Sharp Quattron technology?

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eaclou

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Hey, so I saw an ad on TV about Sharp adding a fourth (Yellow) sub-pixel to their TVs, and I'm just really skeptical about it and curious if anyone knows how it's supposed to work.

I realize that in theory a 4th Primary can increase the gamut because you now have a square-shaped area to work with rather than a triangle, but that side of the CIE diagram doesn't look like it would gain that much from another primary on that side, as it's almost a straight line for the monochromatic pure spectrum colors there. Cyan looks like it would be better than yellow.

Also, and this is really confusing: where is the TV getting the yellow data input? As far as I know, digital input only provides the RGB channels, no video source I know of is recorded with a yellow channel. Does the TV have an internal processing that calculates the 4 values of the primaries from simply the RGB values? This doesn't sound like it would be very effective...

Someone please enlighten me on how this technology actually works and how it could possibly make much of a difference at all.
 
There is a thread on avsforum with some good info.

http://www.avsforum.com/avs-vb/showthread.php?t=1214048

I'm following the tech on these new UV2A panels closely, I'd really like to get one. The main feature I like about them are the increased black levels. The terrible blacks on LCD's currently is what's preventing me from buying one. Hopefully these UV2A panels from Sharp will be the ticket to ride.

The added yellow display element is a bonus. Skin tones never look accurate on LCDs to my eye, nor do certain shades of gold & brass colors. The additional yellow sub-pixel is supposed to help in these areas.
 
I didn't see anything really about the quad-pixel technology in that thread, people were more interested in the panel type.

Anyone know how the TV generates a "yellow" level? (0-255 i'm assuming) Does it interpolate from the RGB, or is there a 4th input channel, or...?
 
Purely speculation:

TN panels only really do 6bits of color per subpixel.
The signal comes with 8bits of data per color channel.
Most panels deal with this through interpolation.
Adding a 4th 6bit subpixel would be an improvement?

Again, this is all probably wrong. Anyone willing to correct me with real info?
 
Thanks, but again, all they say is that there IS a fourth, yellow pixel, rather than any details about how they actually calculate or receive 4-channel inputs, or exactly how yellow is superior to red+green
 
ave0000 said:
Purely speculation:

TN panels only really do 6bits of color per subpixel.
The signal comes with 8bits of data per color channel.
Most panels deal with this through interpolation.
Adding a 4th 6bit subpixel would be an improvement?

Again, this is all probably wrong. Anyone willing to correct me with real info?
Click to expand...

The TV's aren't TN though, they're *VA.
 
Because the very last thing LCDs need are brighter whites. Any modern LCD can get up to a brightness level best defined as "eye-searing". A white sub-pixel won't increase black levels which is the way you'd want to improve the static contrast of LCDs.
 
eaclou said:
Thanks, but again, all they say is that there IS a fourth, yellow pixel, rather than any details about how they actually calculate or receive 4-channel inputs, or exactly how yellow is superior to red+green
Click to expand...
They don't receive 4 channel input, they process the normal input and work from there. A dedicated yellow is superior for the same reason cyan or magenta would be, it's a primary that will extend the gamut and ideally has a better (or no) bias compared the red+green combination. They probably chose yellow instead of those because it's a more frequent color in the world and your eyes are more sensitive to it than blues.

Is it worth it? Go look at one yourself, for the most part it's probably just another trump in the HDTV arms race.
 
It looks like another "Hz" type feature thats gonna end up overblown in reality. Will it make colors richer and give the sharp panels featuring it a upper hand in this display wars? No .. while it may look slightly different it won't make the dramatic impact improved contrast raito would.

The reason why so many companies focus on contrast ratio is its the one of the first things you notice about a TV , it pops out and for the most part plays the biggest role. Adding colors to the spectrum range of the TV set sounds good in theory (kinda like adding different color inks to a printer) but will it result in a vastly improved picture? No.. unlikely.
 
Ryom said:
Because the very last thing LCDs need are brighter whites. Any modern LCD can get up to a brightness level best defined as "eye-searing". A white sub-pixel won't increase black levels which is the way you'd want to improve the static contrast of LCDs.
Click to expand...

Seems to me if the panel lets more light through you can turn down the backlight, allowing for deeper blacks with a similar white output to a panel without the fourth pixel. My armchair speculation is as good as yours, though.
 
A white pixel would make it easier to create neutral grays, but the display should be calibrated anyway so that is a moot point. The problem with that is that only 1 out of 4 sub-pixels is then creating the neutral colors (black-gray-white) cutting your effective resolution way down for neutrals (such as black text on white background, where you need resolution the most) so you would have to use the other sub-pixels anyway, and you are back where you started.
 
Here's a bunch of new details about the technology, although I doubt it goes into anything deep technically but it's something I have not seen posted here yet.

Sharp Quattron slides

I'm definitely interested, especially the high resolution part, more pixels is always a good thing especially if they make smaller panels for PC users then it could really enhance pc gaming.
 
Here is what I think is the key piece of the artical:

This diagram shows the range of color, or gamut, the Quattron can produce compared to the standard HDTV color gamut (spelled out in Rec 709).

?Is a bigger gamut better? Not from a color accuracy standpoint. Most critical viewers, including CNET, prefer to have the TV's color gamut match 709 as closely as possible (more info), and we take note of TVs that can't in the "color accuracy" section of the review. According to Sharp's reps, none of the TV's presets are designed to hit 709 without adjustment. It remains to be seen whether the sets' color management system allows correction of the gamut.

Sharp's reps expected our question on this topic, and claimed that the TV's processing is specifically designed to translate incoming signals color space to best take advantage of the extra space in the displays' gamut. That might be the case, but our contention is that color should be reproduced according to an accepted standard to come as close as possible to the source material.

A rep also claimed that Quattron TVs will be able to produce more colors than current TVs, but we're skeptical that major differences will be visible. It's hard to say for sure, however, and since this technology is so new, there could well be other color-related consequences, beneficial or otherwise, to having an extra yellow pixel.
Click to expand...

The bottom line is oversatruation due to expanded color gamut; no thanks! They are creating the yellow values from the RGB source material. From my education and experience in digital signal processing, this is never a good idea. Same is true with increased resolution, you cannot add what was never there in the first place. We did a bunch of studies on this when I was working in imaging radar at JPL.

All of the TV vendors need to quit doing this kind of something for nothing marketing BS and focus on QA IMO.

Dave
 
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