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RGB to become RGBCMY
elgatozorbas writes "The basic color elements of television have not changed much since 1954; a half-century after RCA introduced the first color set, the RGB (red, green and blue) system used then still prevails. But Israeli company Genoa Color Technologies has broken the RGB barrier by adding one to three primary colors such as yellow, cyan and magenta, thus expanding - from 55 to 95 percent - the coverage of the visible color gamut. The promised result of this multi-primary color (MPC) technology is a television picture that, with its truer, more vibrant color and brighter image, looks more like cinema than video. Also covered in IEEE Spectrum."
Does this mean I should hold off on buying an HDTV?
It's almost enough to make me wish I was a mutant mother of a color blind son.
Certainly makes one wonder what happened to three-color retinas...
A truly revolutionary idea would be to include and project IR and UV in addition to RGB/CMY. Even though our eyes can't exactly 'see' IR and UV, they still form an important part of our realistic image perception. It's not unlike sounds above 20-25kHz in pitch; we don't 'hear' them, but our brain perceives them nonetheless and they are used for stereo imaging of a space.
Cretin - a powerful and flexible CD reencoder
Cheers,
Erick
http://www.busyweather.com/
Sometimes the most mundane improvements can be the best. All the people who swear by HDTV will be SOL, because they'll have hi-res, but improperly colored, television/movies.
My friends are going to be viridian with envy!
There are a couple of factual errors in this story that makes me feel uneasy.
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From the spectrum article:
While film used in cinema contains pigments that can create an infinitely large number of color variations, TV sets combine discrete amounts of red, green, and blue light to create a much more limited color range.
This isn't true: color slide film uses three layers, just like monitors do: http://www.imx.nl/photosite/technical/E100G/E100G
He says that in printing it's common to have inkjet devices that use six, seven, or even eight primaries.
There are good reasons printing uses so many primaries, but it's usually to make an evener tone. My consumer-grade printer has the traditional CMYK (cyan magenta yellow blacK), but it also has two additional colors: light-cyan and light-magenta. They chose these lighter colors so make the blending smoother and the ink spots less noticible; it wasn't to increase the gamut. Printers also use spot-color to make particular colors (such as a company logo) print without needing to use a halftone. These are all just gimicks to get around the fact that printing isn't continuous tone -- in projectors that are continuous tone, these tricks aren't needed.
Basically, it comes down to eyeballs... if you emulate the response curves that your eye is sensitive to, then you can't perceptually do any better.
The traditional RGB's and CMY's don't match these curves, so they define a gamut that can be improved on. For example, take this projector's gamut -- its green is far away from the eye's green, so it can't display the cyans well. But, the color model my company is using for its video product uses a much truer green so we can cover much more of the gamut.
disclaimer: IANACE (color expert), but my most recent project has been color calibration to precise standards.
HIV Crosses Species Barrier... into Muppets
they're talking about combining the two, not switching to cmyk, so you would have 4 to 6 elements (RGB plus 1-3 others) which would give you "truer" color reproduction than rgb alone
at least that's my understanding.
I want to see what it looks like.
Lasers Controlled Games!
16 million colors should be enough for anyone.
Adding two extra colors to this kind of projection television has little impact on the price tag, says Simon Lewis, vice president of marketing at Genoa. He says the new Philips color-enhanced set, to be available next year, needs only a few additional filters and optical components to create the yellow and cyan light, with no changes to the more costly microprojection chip.
Right. Right when we've got all these plants around the world cranking out inexpensive TV's using LEDS and LCD, some whizzo comes along and says, "Hey, look, a great idea and all you have to do is retool everything, develop some newer technology and keep selling it all at the same pricing you're currently at!"
Perhaps the main challenge in converting a video stream from a three- to a five-primary color system is doing it in real time, says Maureen C. Stone, ...
Yay, now we really will need a computer in every TV! More components - more to go wrong, more power consumption, etc.
"How the algorithm does that, precisely, is a secret well kept by Genoa. "It's part of their intellectual property," Stone says.
Yay, more intellectual property. This should drive prices down.
<curmudgeon>
Why, back in my day we didn't have remote controls and we had a folded playing card stuck beside the tuner knob to keep the picture from doing funny things, and we liked it!
</curmudgeon>
I'm sure it will look lovely, while watching older stuff from the bad old pre RGBCMY days.
"Gilligan!"
I'm like, totally there, dude!
A feeling of having made the same mistake before: Deja Foobar
There are three primary additive colors and three primary subtractive colors. Cecil explains it rather well.
RGB is a set of orthogonal colors, and a linear combination of RGB can express any color in the universe. Similar comments apply to CMY.
Adding CMY to RGB to create RGBCMY does not buy you anything. Hence, the message starting this discussion thread is misleading.
Why is the television signal so poor in generating an image? The answer is unrelated to RGB. The answer is the the following. Prior to transmission, the analog RGB signal is converted into the digital YCbCr signal. (YCbCr is also an orthogonal set of colors.) Y, luma, is sampled at a reasonable rate, but the sampling system samples Cb and Cr at only half of the sampling rate for Y.
My guess is that RGBCMY is simply a clever attempt to use CMY to restore some of the samples of Cb and Cr that were discarded.
disclaimer: IANACE (color expert), but my most recent project has been color calibration to precise standards.
Parent has very good info, but if anyone wants additional reading, this guy is a color expert
(S(SKK)(SKK))(S(SKK)(SKK))
Far violet (~400nm) and far red (~700) are both visible. They might make the viewing experience much richer, and light at those wavelengths won't damage skin / eyes or cook your dinner.
Si la vida me da palo, yo la voy a soportar Si la vida me da palo, yo la voy a espabilar
That's JUST what we need, more reasons to watch a box all day. I can look out my window and get all the colors all the time. And since I don't watch TV, time is something I've got 28-42 extra hours of every week.
Tell me you're not in denial - and I won't listen.
Stuff that matters.
NTSC throws away 3/4 of the colour information, and even HD throws away Half. From the article, it seems as if the chip is doing a lot of guessing and not "really" incresing the colour resolution. This sounds like a good way to go, since the Codec on the DVD won't have to deal with those extra colours; it's handled at display.
This is true, but more colour depth is often needed in compositing work. It's not uncommon for a visual effects shot to be handled at 16 bits per channel, or twice the colour resolution of a 24 bit image. The reason is that it has a greater dynamic range. If you add two bright pixels together, the result will be white. But with more bits per channel, the pixels will be brighter than white, and still maintain values relative to other pixels, so that if you darken them later, no information is lost. Visually, 24 and 48 bit colour are indistinguishable.
Not true, there are a few colors that are out of gamut on an RGB display.
-jim
Most folks don't realize, but there really are four primary colors. Most geeky types are familiar with the red, green, and blue cone cells in our eyes -- but the rod cells that are used for night vision have their own separate response spectrum, weighted heavily toward the blue/violet end of the spectrum.
That means you have four separate "detector systems" in your eye, each of which is sensitive to a different slice of the optical spectrum. In particular, you can distinguish shades of violet and magenta that differ only in the blue-cone/rod response levels.
Ever think about why blue light is used universally to signify "darkness" or "moonlight" on stage? It's because, in low light levels, your cones shut down and your rods -- which in bright light connote blueness -- are the only part of your retina that works well.
It's also the reason why night-vision flashlights are red, and why blue LEDs appear so bright when used as flashlights. The red light doesn't stimulate your rods, preserving their sensitivity; and the blue light gives you extra rod stimulation per unit power, making blue LEDS very efficient as nighttime illumination.
I'll wait for HDR display and feeds, thanks.
Judging from the gamut chart for this RGBCMY, the boost in color range is primarily in yellows and cyans. Gold, as they note, would be a good application. Cyan.. well, that's mostly skies - and those already appear just fine on TV. A fairly decent increase in magentas/purples as well (when taking the assymetric lobe into account), but again.. not seeing its application much.
Unless following the British royal family (lots of golds and purples) a lot, it doesn't appear to offer all that much. Especially considering movie people butcher things anyway (DVD gives a more stable picture, sure.. at the compromise of mpeg artifacting and even encoding issues.. twitches ever 25 frames are annoying - luckily only a few suffer from this).
On the other hand, a higher dynamic range would be immediately noticeable anywhere.
A sequence with the sun glaring into the camera ?
A car's headlights shining at the camera ?
Highlights on objects ?
Blown-out surfaces from bright lighting ?
All that could then more accurately be represented. And thanks to most things still being shot on film, or already on 10bit CCDs with, formally, underexposure but a gain for the operator, a good bit of extra range is already available in previous and current productions.
Whilst RGBCMY would only really be of use for film (as in, actual film) productions, as digital cameras are in much the same RGB limbo that current displays are.
Wow, this is really cool.
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There's a whole bunch of these wide gamut and high dynamic range displays suddenly.
At SIGGRAPH this year, there was a 6-primary (RGBCMY) projection system called IRODORI on display in emerging technologies:
http://www.siggraph.org/s2004/conference/etech/ir
There was also a high dynamic range display (capable of a greater range of brightness) from Sunnybrook Technologies at E-Tech:
http://www.siggraph.org/s2004/conference/etech/hi
And then I saw a few displays on the exhibition floor from NEC with a "WG" specifier for "Wide Gamut". NEC's WG monitor is still RGB but with purer R, G, and B phosphors to obtain a gammut wider than Adobe RGB.
And now there's this one. Way cool.
I can't wait till this becomes more widespread. The question becomes, what will the next color standard be for use in applications and APIs? It doesn't make sense to actually encode color as 6 values for display, since (most) humans only have three kinds of cones. It would make more sense to use something like CIEXYX for color interchange in that case. Especially if we're going to have this wierd mix of HDR and various wide gamut displays around for a while, each which has slightly different needs for color output. Best to just go with a neutral, well-defined intermediate colorspace.
CMY(K) are Subtractive Colours. (You add them together to get black)
... RGB + CMYK negate each other.
... while LCD's naturally use a CMYk approach
Hehe! No, this is quite false, quite a number of ways.
First of all, colors of light are additive, colors of pigment are subtractive. This is true regardless of which colors you choose. If you had a monitor using the CYM model, you could not produce red, because monitors, being light emitting devices, are always additive, never subtractive, mixing C and Y would add their lights, not subtract leaving just the G. Because of this, you cannot get a lot of colors. However, you can get white, by adding C, M, and Y together. Since monitors are additive, adding CYM makes white, not black.
The LCDs we use today are light emitting, not light reflecting. Thus, they naturally use an RGB color model. If they did not emit light on their own but only reflected like, like a sheet of paper, then their natural color model would be CYM(K). But that's just not how things work.
"Convictions are more dangerous enemies of truth than lies."
Last week in the emerging technology section of SIGGRAPH a company or process called IRODORI was demoing a six-color projection system. (I could not find a reference on Google or www.siggraph.org.) When side-by-side with a conventional three-color you saw dramatic differences. Conventional is like looking at the world with wax-paper taped over your eyes. They claimed that conventional systems only covers about 55% of the CIE color chart, while they get over 90% color space. They bootstrap off of two conventional three-color projection systems. They put in different color filters and add special color separation software.
Well, true they have to expand the gamut of existing RGB data artifically, but this is different from what you can do in photoshop. In this case the display can actually show more real colors than a conventional RGB display. Put the two monitors side-by-side, and you will be able to see colors on a RGBCMY monitor that simply cannot be reprodced on any normal RGB monitor. Have you ever taken a digital picture of a beautifully intense blue stain glass window, or some brightly colored flowers, and been disappointed when you got it home to see how bland the colors were on your monitor. The gamut captured by the camera is part of the problem, but even if it captured the colors perfectly, current monitors still couldn't display the results. These new wide gamut monitors should be able to do much better.
Having to "make up" the additional color data is just a temporary measure until content creation software and image acquisition hardware catches up to the gamuts possible with these new monitors.
I, for one, welcome our new RGBCMY masters.
And here's what you said: "This isn't a new standard, it's just an after effect applied to existing signals."
While you're right that it can be used in transitional technology, you're wrong that it's "just" an after effect. Nobody would say that Technicolorized B&W reproductions are the same as actual full-color originals. And here, you're going to need a format that preserves color information in the new 5 color system if you're going to exploit the real improvements in this color technology: closer reproductions of actual color.
As I recall, a linear combination of RGB can express any possible color -- if you allow for negative amounts of the components. A really bright yellow might be 1 R + 1 G - .2 B for example.
That's still a linear combination, but just one that's not particular useful in the real world of phosphors and filters.
Thad
I love Mondays. On a Monday, anything is possible.
The method with which you combine colors determines whether they're additive, not the colors themselves.
Remember: It's about emitting light versus absorbing light.
If you have three flashlights with thin plastic in front, one of cyan, magenta, and yellow... When you combine the beams, things will get brighter (of course... Three flashlights). That's because the method being used to create the light is an additive process.
If it were a subtractive process, then you'd be able to make a "flash dark".
Because printing is always a subtractive process (Paper starts white, and must be made darker), the CMY/K gamut is used. (Notice that these three colors are less "strong" than RGB, making them easier to control and combine for printing). In really advanced printing, you can get multitudes of colors, to reproduce more variations, or to get more accurate color (Because sometimes mixing CYM to get perfect tones isn't as effective as it could be).
Keep in mind: We use combinational color models, because we find them managable and convenient. However, these color models are not perfect, and cannot be. We won't ever have it perfect until we're able to serve up colors by frequency, and have them displayed accurately. Even high-quality film is limited by the chemicals used to make the film.
~D
This sig has been enciphered with a one-time pad. It could say almost anything.
RGB, CMY, CMYK, etc... *cannot* represent the entire visible color gamut. YIQ (the one used by NTSC TV), YUV (PAL TV), and YCrCb represent a smaller gamut than RGB, to be sure, but neither represent the whole thing.
For that, you need a more complex model like CIELAB.
Here's some links:
A whole lot of information.
Samsung stating that their shiny DTV sets can't match the visible gamut.
A graph of visible, RGB, Pantone, and CMYK gamuts
There's a huge amount of slop in the brain needed to produce the perception of stable colors of objects under different lighting conditions
:). Alternating between the LEDs (white light) and the bulb (yellow light) was... interesting. My eyes couldn't decide what colour things were. Relatively speaking, sure. But I'd go for a while with just the LEDs, my eyes got used to that, then switch to the bulb. Suddenly, switch to the bulb, and everything gets weird. Even subtle things like depth cues get messed up, because your brain is frantically trying to re-colour what you're looking at.
:)
Boy, you can say that again. For anyone who *really* wants to experience this, I suggest you go caving some time. In a deep enough cave that no outside light penetrates. Last weekend myself and a group were out, and we all had different models of headlamps. Now, the cave we were in has 3 interesting things going for it here: very banded & multicoloured rock, lots of ice (again somewhat multicoloured due to how it forms over the centuries), and human artifacts (a fair bit of paint on the walls, general human refuse, etc).
Here's the trick: you're in an area where your eyes have never seen the surroundings in natural light. Effectively, you have no reference point to know what colour things are. Now, I personally have one of the newer LED/incandescent combo headlamps (an amazing combination by the way, and for those with any doubt, 3 white LEDs will provide more than enough light for at least 20' around you - no more trying to focus right in front of your feet
This really didn't happen with things like our clothing or other gear, because my brain "knew" what colour that stuff was, having seen it outside, and it adjusted easily. But the rocks, ice, and *especially* the tagging on the walls - very creepy effect. Things that looked green in one light could be red in another. The ice was fun, because it's actually somewhat brown/yellowish in some layers (dirt, I suspect). But the brain wants to colour it blue-white.
We also had a good game of "guess my eye colour" - many of these people didn't know each other very well. I think we scored less than 50% overall
Endless arguments over trivial contradictions in books written by ignorant savages to explain thunder in the dark.
No. This is just moronic marketing hype from people who should know better targeting people who don't.
First of all it's not a new idea - we looked into it at apple in the mid 80's as a way of getting more brightness out of LCDs. Using a CMYG pattern for example.
Second, a cursory glance at the CIE diagram teaches those who understand how it works that well placed RGB primaries cover almost the entire visible gamut (90% or so). There just isn't 20% left to add with a few more primaries, let alone 65%. That's not how vision works. (A cyan primary might add about 10%, but a yellow doesn't do much of anything and magenta just isn't a primary).
And third, neither video nor movies are color matched anyway. There's no "right" color for a tv program. It's what you want it to be. That's why NTSC stands for Never Twice the Same Color. Expanding the gamut is just like turning up the saturation on your TV. Is your saturation maxed? If so, you'd probably like a TV with a larger gamut (OK, it's not quite that simple, but video programming is targeted to the typical gamut of a TV, so the new technologies typically have to be turned down or they look a unnatural, as the article described. That is, if you really use the new gamut, it looks borked anyway, unless you like that sort of thing.)
If you've got crappy, unsaturated primaries, then adding more colors can expand the range, but at the expense of monumental complexity in the color math. Comon - getting color matching to work even marginally right with only three primaries is a task yet to be even partially achieved - how many of you have color calibrated monitors? And you want to add more primaries? Get a grip on the 3 you've got!
The press release does speak of a truth in subtractive color displays (like LCDs but not CRTs) that there is an intrinsic trade off between color purity (gamut) and brightness. Of course you can always use a brighter lightbulb/backlight... Or an alternative primary color technology like CRTs LEDs OLEDs Lasers... etc today. Large screen OLEDS would have a far better gamut than this crap anyway.
If you want to see amazing color look to laser displays or Sony's new reflective ribbon technology (that uses a laser as the source) with pure RGB primaries, there's no advantage to be had...
As for the technology being unique or special (not short bus special, though it is that) it's not. Your 5/6/7/etc. color inkjet printer does exactly the same thing. With reflective images (subtractive color) you don't really have primaries, you've got inks, and long ago people chose to print in RGB complement CMY (the K part is just because most inks suck and CMY all togehter would be grey, not black, so they added the black - sound familiar to the story? That's only about 100 years old). Anyway, looking back at our old CIE diagram we see that Cyan Magenta and Yellow inscribe a wee triangle even with fully saturated inks, so Epson chose to add a few more colors (and then more, and more) and figure out the color math behind the transformation from CRT RGB primaries (or CIE LAB) to CMYKC2Y2M2 etc. It works well with printers (Epson was actually copying Pantone's Hexachrome offset process, which itself is probably not the first).
It's an OK idea to improve the image quality of the color mixing functions used to filter incoming light for color cameras (typicaly CMYG, though some cameras now use RGB), but it's just silly with LCDs. If you're really a color fanatic you're probably using a CRT anyway.
As an aside, in the persuit of some research about 10 years ago I found a paper article presenting research in capturing archival images of paintings and other works of art, and seeking to eliminate all possible metamerism between the color mixing functions of the detector and the human visual system. The authors found that to do so required a 7 primary system. I haven't been able to find the article again and I'm not