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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."
I wouldn't. It's taken so long to get HDTV "standard" that it will take just as long to get this new standard in. If everybody just upgraded to HDTV, they won't want to upgrade to this. These guys were about 5 years too late it seems :(
Just because you don't understand a word doesn't mean it's offtopic.
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.
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.
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.
"Maybe it's because we're spoiled with the high resolution of computer monitors, but I can barely stand to watch normal TV"
... true, it's due to the poor-man's anti-aliasing and huge-ass pixels on a TV ... and the effect can probably be replicated given a specific set of video filters for your computer ... however, for the truly lazy video pirate, nothing beats a regular old 4:3 tv.
Normal TVs are better at displaying low-bandwidth video streams (think VCDs)
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. html
Actually, the statement you quoted is perfectly true. The fact that color slide film uses three layers does not in any way contradict the statement you quoted. The word you appear to have overlooked in your quote is discrete. Because three layer color slide film is nondiscrete, it had precisely the ability the quoted text says: it can create an infinitely large number of color variations. Since TV sets vary these three colors over a discrete range, they have an infinitely more limited color range.
"Convictions are more dangerous enemies of truth than lies."
Not really. The thing is, everyone's eyes are different.
As you probably know, our rods respond to the intensity of red, green, and blue light. More specifically, each type of sensor has its peak sensitivity at approximately those colors. Our red sensor responds a little bit to blue light, our blue sensor responds a little to red light, etc. Our eyes "know" there's a given wavelength of light based on the output from all three sensors. Thus, we can duplicate the effects of any color just by using colors at these peak sensitivities.
But...everyone's sensitivity curves are a little different. In the extreme cases, we call it color-blindness. Here are some color-blindness sensitivity curves. There, the mapping is different. If we have RGB output that looks exactly like a physical object to us, it might not look the same to them. (The two will neither look how we see it, or like each other.)
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.
What you have described is the logic behind Component Video. But to fully exploit the diffrence a 4th wire would need to be implmented. You would have the regular RGB plus the luminance. Componenet Video uses 3 cables signals to deliver all 4 componets you described:
Component video consists of three signals. The first is the luminance signal, which indicates brightness or black & white information that is contained in the original RGB signal. It is referred to as the "Y" component. The second and third signals are called "color difference" signals which indicate how much blue and red there is relative to luminance. The blue component is "B-Y" and the red component is "R-Y". The color difference signals are mathematical derivatives of the RGB signal.
Green doesn't need to be transmitted as a separate signal since it can be inferred from the "Y, B-Y, R-Y" combination. The display device knows how bright the image is from the Y component, and since it knows how much is blue and red, it figures the rest must be green so it fills it in.
No, that's just women. Being steeped in the makeup/fasion industry all her life, she had a much larger color vocabulary than you did. You can distinguish between different shades of red as easily as she, but you simply don't have the vocabulary to name them.
And not only does she have a complete vocabulary for different hues of "red", she also has a vocabulary for different saturations of "red". After all, "ruby" is about as pure red as you can get, but that wasn't the "red" she wanted, was it? Odds are it was a much lower saturation, probably on the order of "M&M Red".
Of course, each woman has their own unique color vocabulary. I used to work in interior design, and different women used to name the exact same color swath differently. And heaven help me if they wanted to see a "taupe", because they could have meant anything from "doeskin" to "peach". It all depends on their particular exposure to makeup and fashion marketing.
Don't blame me, I didn't vote for either of them!
Won't this require twice the bandwidth to transmit?
Read my keyboard review.
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.
Some DLP projectors I think use red, green, blue, and white to get some of this contrast back.
No that's not for contrast, that's for peak brightness. Since all colors those devices can generate are linear interpolations of the filtered colors, all you can get with white thrown in is bright, non-saturated colors.
Your cyan pixel, letting through both blue and green light, would be brighter than either your plain blue or plain green or blue&green next to each other.
But you couldn't make all things brighter. If you increase the number of filters, the time and amount of light for each filter decreases. Pure red, green or blue could not be displayed as bright as before. Only colors close to those added and desaturated colors or grays would profit from this.
It's not the discrete gaps that are the problem! RGB does not represent all of the visible colors, even theoretically. Assuming a perfectly smooth RGB model with infinite intensity and perfect black, and infinitely precise levels of R, G, and B, there is a huge chunk (around 45%, if I remember right) of the visible gamut that is totally unreproducible. CMY covers some areas that RGB doesn't, and vice versa. Neither is the whole gamut. There are more complex models that do, like CIE L*a*b.
RGB's aren't "additive colors" and CMYK aren't "subtractive colors." They're all colors, and you can mix with them any way you like -- adding or subtracting.
You wouldn't call a painter "counter-productive" for having red, green or blue paint, would you? Then what's so wrong about a screen having Cyan, Magenta, or Yellow?
See, there's two ways to mix color: adding them (shining multiple light sources upon a surface, or directly at a receptor), or subtracting them (mixing multiple pigments or overlapping multiple light filters, then shining white light on or through them to produce the color).
RGB are the additive *primaries*, and CMY are the subtractive *primaries*. But the notion that "R G and B add, and C M and Y subtract" is completely misleading.
The following sentence is true. The preceding sentence was false.
It's funny, cause when I read the headline, I thought 'what the Hell kind of good will that do?', but after a little thought, this started to sound useful. I had never tried to think outside the RGB world because it 'technically' displays all colors, though it struck me that the colors in-between RGB will come out dimmer than they should.
I think the first thing to spring to graphic artists' minds is 'when can I get a monitor like this?' And also, how much of a strain would it be for a video card to compute three new colors (while not needing their values upfront).
I figure, most printers also work by CMYK values, so previews would be more accurate. It seems like this would have all sort of uses.
And, yeah, all CMY is is a shift down in the hue from RGB:
Cyan is between green and blue
Magenta is between blue and red
Yellow is (of course) between red and green
I am NOT a number! I am a - oh wait, I'm number 761710. Look! 761710!
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
...it's a mixture of red and blue from opposite ends of the spectrum. Cyan and yellow both depend on equally exciting both the green & blue and the red & green cones equally, but that can be accomplished by a swingle wavelength, unlike magenta.
I don't know why they bothered. RGB are the additive primary colours, whereas CMY are subtractive. I can't see whta value you'd get from adding subtractive primary colours to a device which emits (rather than reflects) light. The manufacturers obviously expect (probably correctly) that most people know jack shit about colour theory.
What a long, strange trip it's been.
The problem is, and I'll admit this, that different people percieve color differently. While there might be a model that you can call a "typical" human eye color gamut, you need to go to hard physics ultimately in order to pull out the other colors.
Photoshop experience and an artistic eye can pull out colors to make them more life-like and even treat the other three colors in a hex printing pallet like colors on an oil-based paint pallet, but in reality you can't obtain new information that isn't there unless it was encoded in the first place. You add a little bit of that information with a good photoediting piece of software like Photoshop. An RGB color space is fairly good, and a reasonable model, as is the "color wheel", but it is just one model that works reasonably well. There is a point that ultimately it breaks down, and that is the point I was trying to make earlier. That you can create 70%-80% of all of the colors in human experience makes them very useful models, especially as the remaining colors are seldom seen by most people, and there are many other issues involved with art like proportion, balance, and perspective that are just as important if not more important. That colors get pretty close means you can concentrate on the other issues instead.
Trying to explain the value of even an RGB system is quite difficult to those who are color blind and barely see two colors, or are purely monochromatic in their vision is particularly difficult. What is worse is that often they don't realize that they don't see all of these colors.
My background is more along trying to engineer systems that can accurately display and portray colors for most people, which is why I have gone more for a purely scientific viewpoint. Having to deal with more unusual color gamuts like a pure RG system (systems that only display red and green, due to costs to add blue to the display), and RGBW systems (where you have the normal RGB and add white for additional contrast... and you though CMYK was tough). I did some limited experimentation with violet LEDs and some very dull near infared LEDs as well. They give some colors that are quite interesting, and unfortunately I never had the chance to see a full display made up of these colors tied together with RGB LEDs, like is being suggested by the article mentioned as the parent article. While understanding the physiological issues regarding color perception (and we did deal with them), we had a much easier time dealing with color from a raw physics viewpoint when designing our systems, in part because we were working on a more physical system level. I had to also deal with the user interface and trying to come up with a color picker that would work with these sometimes unusual color spaces.