Slashdot Mirror
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.
If the CMY(K) color space is smaller than RGB, then why would it look more like cinema?
Certainly makes one wonder what happened to three-color retinas...
Steps towards more realistic pr0n are always welcome. :)
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
Last I knew there were colors (the actual spectrum of light) and then there were pigments of things (which actually reflect certain colors of the light)
so now they can project reflected colors, aka pigments? hmmm
?SYNTAX ERROR IN LINE 42
Cheers,
Erick
http://www.busyweather.com/
Just because you don't understand a word doesn't mean it's offtopic.
While it sure does sound good, I high doubt that anyone will want to throw away the billions invested in good old RGB tvs and monitors. After all, they're "good enough."
I wonder why green was chosen instead of yellow all along, since green can be formed combining blue and yellow.
Open Source Java Web Forum with LDAP authentication
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!
Clever product advertisement wrapped neatly into small slashdot article.
There are a couple of factual errors in this story that makes me feel uneasy.
. html
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
I want to see what it looks like.
Lasers Controlled Games!
oh, wait a minute....
I'm a writer, a poet, a genius, I know it. I don't buy software, I grow it.
...you still won't have a colour-calibrated monitor unless you're a graphics professional, and probably not even then. :(
Here's an example of the improved color gamut you can get by adding a few more colors. Try it out!
Before
and
After
Can the human eye even distinguish between such fine variations in color? I know I've never found any flaws with images rendered in 24-bit color.
This space intentionally left blank.
Most people do not regard gamuts and colour spaces as important in their purchases. perhaps with the critical mass of photography and printing people may start to be more concerned.
I for one have given up trying to get Photoshop to display the colours correctly...
And who cares about increasing the colour space, when the networks are forcing everyone onto digital, highly compressed channels, and also making people buy higher resoution sets, which will lead to higher compression, and loss of colour information though that way.
High fidelity tv should be that... I am not a tv expert person. I just watch Seinfeld.
#hostfile 0.0.0.0 primidi.com 0.0.0.0 www.primidi.com 0.0.0.0 radio.weblogs.com
16 million colors should be enough for anyone.
... we have to add Luminance and Alpha as well. and then perhaps Reflectivity...
So we have RGBCMYLAR. Yup, much better.
-3Suns
~~~~
The Revolution will be Slashdotted
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
I wanna know if I can tell the diff between it and my RGB CRT.
There are three primary additive colors and three primary subtractive colors. Cecil explains it rather well.
What ever happened to 64bit colour displays and videocards? I remember there being a bit of a buzz about it a few years ago, haven't heard anything since.
everyday is another shooter.
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))
Whoa another great reason to buy (licence) all your favorite movies all over again.
This won't be a fully complete standard until they include squant in their color model.
--
"Open source is good." - Steve Jobs
"Open source is evil." - Microsoft
RGB and CMYK are counter-productive.
RGB are Additive Colours. (You add them together to create White)
CMY(K) are Subtractive Colours. (You add them together to get black)
CMYK has been used in the Colour-copier/printer industry for a long time. It depends on using White paper to 'iluminate' the colours that have been added.
RGB + CMYK negate each other. Considering that any combination of RGB can give you any colour, CMYK can't (for example) give you 'floresent' colours {without cheating}.
CRT's use glowing phospher (sp?), LCD's use a white-light to illuminate the coloured pixels that have been turned 'on'. By this definition CRT's naturally use an RGB approach, while LCD's naturally use a CMYk approach. I think it's just been a faulty evolution to keep LCD's emulating the RGB approach. this CMYK idea will only work if the video card companies make seperate product lines.
"The price good men pay for indifference to public affairs is to be ruled by evil men." ~Plato (427-347 BC)
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.
That's the problem with technology, it keeps moving forward and at some point you have to buy something and watch it rapidly become a POS. Exacerbated by how much you spend when you do buy. There's probably a lesson there, but I can't divine it - I'm still trying to figue out the benefits of RGBCMY in relation to the sh!t they call television programming these days. You want real quality viewing of movies? Build a home theatre with a BIG screen, like 64" or more. It's probably a blessing to have poor hearing and bad eyes... probably saves no end of money.
A feeling of having made the same mistake before: Deja Foobar
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.
RGBCMYLARLOLBBQ
...it's true. When I was younger, we used to look at tubes and panels for information from our computers. I'll never get the hang of using these cranial implants... damned pop-ups! Why am I always thinking about sex and enlarging my penis!?
What would REALLY be awesome is if we had monitors that could display light as we see it in reality, ie a full spectrum of wavelengths. RGB just uses pyschological tricks to make our brains into thinking we seeing multiple colours.
more vibrant color and brighter image, looks more like cinema than video.
Bollocks. If you want it to look brighter like a cinema, drag heavy dark-crimson curtains over every possible light source and tread stale pop-corn into your carpet.
What this doesn't do is improve resolution, which is the principal deficiency with home systens. But give that is a problem with the source material rather than the display.
Norman Cook's Ode to Sl
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.
Sigh... Has no relevance.. The color space of television is limited because the phosphors in the tube are limited....
The samples are discarded because the human eye doesn't see them anyway. Color TV is an early form of video compression.
Why the heck does news like this come out 2 days after I drop a load on my new 60 inch HDTV?! :|
Great - 8 gazillion colours and still nothing but crap to watch.
Various video media may not have the necessary color resolution to drive these displays, but (given quality art assets;) newer video cards do.
I wonder how these types of displays compare to Iridigm's upcoming products on color fidelity. Those look quite interesting, especially at effective 200 DPI.
Galileo: "The Earth revolves around the Sun!"
Score: -1 100% Flamebait
hahaha, finnaly my color blindness pays out! i can't see half them colors.....
The sales pitch gives the impression that the colors will be more true to the original (as in film) but in reality it looks like they are just taking the same old (post-lossy compressed) RGB data and making it "more vibrant". Not the same thing. At all.
--This sig is in beta. Please let us know abut any errors you find.
I sure do miss Roy G. Biv...
Real advancement would be discovery of emitters that can match the XYZ Color standard. This standard was designed to mimic the actual operation of the eye, and therefore its gamut includes all possible human-observable colors.
If I have been able to see further than others, it is because I bought a pair of binoculars.
The way I see it, TV is more than I'll ever need. It looks quite nice, and it allows me to view cheesy made-for-tv movies featuring sordid affairs and people dying violent deaths thru use of firearms. No really, TV is TV. We don't need anything better that costs more money, for that we have computers. If I want to watch a movie, I go to the local video store, rent one of the projectors for 5 bucks a pop, plug it into the PC, and there is a movie, in all the colors I'll ever need. I've got 16.7 million of them to choose from, so I'm quite happy :p
Red would indeed be a better green, If only it was a little less yellow.
Sorry, I don't believe this marketing hype. There are three primary colors because our eyes detect three different wavelengths of light. 24-bit RGB color can produce every variation of color that the eye is capable of percieving.
...welcome our new RGBCMY overlords!!
This sounds like another technology that improves upon something nobody ever complained about. Personally, I'm as happy watching an old VHS tape on my 15 year old 25" Toshiba TV in the bedroom as I am watching a DVD on my 32" Sony Wega with surround sound. Yes, the DVD and Wega offers a better picture, but it doesn't improve the experience for me.
Never have I complained about lack of colour on my TV, yet in 15 years will I be looking at RGBCMY in my living room and telling people it doesn't improve upon my old Sony Wega?
I want to control the camera angle and watch in 3D. Now those are improvements that would be worth paying for.
The global economy is a great thing until you feel it locally.
I still have a 19" Montgomery Wards TV that my parents bought in the early 80's. Only get two channels CBS and PBS and I am still alive! If I want to watch something interesting I get a DVD (did need to get a RF modulator for the DVD player). I couldn't see spending thousands on a HD Widescreen digital integral tricyclic circuit system, would rather buy a new car.
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.
while the RGB color space may be able to display any color, the RGB phosphors are not. So its possible for the CMY phosphors to be able to enhance and expand the color space that the normal set of color phosphors can show.
Ignorance speaks! RGB is a basis set only if you allow negative values of color. What does negative red look like? (Hint: it isn't green)
I think you probably mean 'linearly independant', not orthogonal. And I don't think they do span the whole colour space, unless you allow negative amounts of red green and blue (which you clearly don't).
Have you not seen that diagram where R, G and B form the vertices of a triangle in some kind of colour space - the area in the space which the eye can see is slightly bigger than the triangle, with curved edges. I would find a link but I'm lazy.
Depending on the technology (small mirrors or liquid crystal), the silicon switches pixels on or off when the color is aimed at it. Intensity of the color is handled by cycling the pixel on or off (only possible at semiconductor speeds). Light is reflected from the small mirror or substrate underneath the liquid crystal pixel and shines on the screen. The combination of the RGB colors together at high speed creates the image.
To add 1-3 colors to the color wheel and add support for that color to the silicon should not be too much of a technology hurdle. All you need is a faster color wheel and faster switching silicon to handle the additional colors without slowing the refresh rate.
Wow, this is really cool.
o dori.php?=conference
g h.php?pageID=conference
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.
Actually, there is no such thing as inherently "additive" and "subtractive" colors; what happens is when you project light through a colored filter, the colors are additive (cyan, yellow, and magenta filtered light will blend to white just like red, green, and blue will), and when the light is reflected from them (as in the case of pigments applied to a surface), they are subtractive (red paint plus green paint plus blue paint will give you black, just like CMY paints or inks will).
Got mead?
It's all well and good to improve the picture quality, but this doesn't address the main issue of TV today. The content sucks. We're now down to maybe one or two good shows, about 20 cop-dramas, and about 1000 "reality" shows.
Let's stop trying to make the mechanics better, and actually make something worth watching.
It's good to use your head, but not as a battering ram.
...do anything to fix the substandard programming?
-- Even if a god did exist, why the fsck should I worship it?
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.
In particular, if one judges the 'distance between a two shades of red using a RGB colorspace, and compares that to two similar distances between shades of blue, they would guess those distances to be wildly different.
the cie color space is far more accurate for displaying percieved distances between colors.
Now with even more visible colors, it'll be even more obvious that your tint control is horribly off. Let's hear it for phase drifting!
That's great. Now I'll be able to see the pointless, demeaning, vapid content in the most precisely tuned shades of green the world has ever known!
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.
And since NTSC (never the same colour) is notorious for not being able to display yellow or other "hot" colours, some improvements would be nice.
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.
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
No, this isn't even remotely true. Even if we assume you only meant the visible spectrum, RGB still only covers a small section of it (well, ok, a little more than half of it).
For example, how do you generate a true violet colour of around 400 nm when the blue in RGB is usually 450 nm? It can't be done (well, it can be faked but see below).
For more info about the colour gamut of RGB I recommend you go here:
http://www.cs.bham.ac.uk/~mer/colour/cie.html
Really, RGB only really works because it's a close match to the 3 colours our eyes are sensitive to. The mapping of RGB to wavelength is based on purely empirical Colour Mapping Functions. Even then the CMFs fail for certain colours such as those around 500 nm (i.e. your monitor can't reproduce 500 nm).
RGB could express any color in the universe only if devices could produce any level of intensity of a component (a continuous scale). As it is, most devices only produce a limited range of intensity, and discrete levels of intensity at that.
So RGB allows you to hit any colors in a three-dimensional 'grid'. Adding CMY adds more bases and therefore provides a way to cover some of the in-between areas in the grid. I assume that it's more cost-effective than trying to make a finer grid (by increasing the number of intensity levels).
Did someone forget the color that pops off of the TV screen and starts licking your balls? I specifically asked not to forget this one; it is the only one that mattered...
If carrots got you drunk, rabbits would be fucked up. - Comedian Mitch Hedberg R.I.P. 03/30/68-2/24/05
I can buy an audio calibration thingy for $25 or so but to raise the detection frequency a little to RGB it gets much more expensive. :-(
Any colors can be used in an "additive" or "subtractive" fashion, depending on whether they are generated or reflected. It's just that RGB has traditionally been used for additive applications and CMY(K) is typically used for subtractive ones. There's no fundamental reason, except for convention and ability to match the human visual gamut, that you couldn't have a CMY monitor or an RGB printer (though of course these would have different gamuts than existing devices of each type).
My elderly friends had a useful remote control - their rotary channel tuner had a pulley system attached to the ceiling with which they could easily change channel from their bed. You just had no DIY skills :-)
this is really great news. however, i wonder what the new DVCs will cost with this technology. i have been in the market for one and now kind of want to wait and see what comes of this.
Visit the Mother Site !
http://www.spectrum.ieee.org/WEBONLY/resource/aug0 4/0804ntvf1.html
link to a chromacity diagram from the Spectrum article. No triangle in the diagram can cover the whole diagram. The RGB phosphors are far inferior to pure RGB, and the 5-color system is a significant improvement. Note that just using their green in a 3-color system would provide half of the improvement they claim.
Contribute to civilization: ari.aynrand.org/donate
Won't this require twice the bandwidth to transmit?
Read my keyboard review.
still nothing to watch.
some convoluted color-space anti-aliasing technique. Since the signal is unchanged from the original source no new information can possibly be conveyed through adding cyan and yellow to RGB. Afterall, the data on the DVD is discrete and so any yellow they get is obtainable as a linear combination of the red and green, and any cyan is a linear combination of the blue and green. As far as I understand anything that does not change the sampling frequency of the colors cannot affect the number of colors portrayed and thus is just an anti-aliasing hack.
You can get noticable banding with 24-bit color. 8 bits for intensity (per color) is too small. 10 bits would be OK with the right correction curve (non-linear). 16 bits is often used for critical applications like radiology.
Mea navis aericumbens anguillis abundat
I use Lynx, you INSENSITIVE CLOD!
Akasaka Natural Vision Research Center presented some of their technology 6-band HDTV Camera, 16-band Micorscope, 6 primary DLP Projector, etc.
Personally I find this more interesting then the article sence they expose what they are doing. As well as addressing the multi-primary capture issues as well.
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
It seems perfectly clear, that it is RGB..................55% CMY.................+40% M-O-U-S-E.............5%
I'd love to help you out -- which way did you come in?
Hmmmm.... I wonder how our eyes perceive the even and odd order harmonics resulting from blending colors of the spectrum and distorted waveshapes of light?
Kinda like our ears hear the harmonics produced by complex audio waveforms and the blending of multiple audio pitches.
As others have pointed out, the RGB colorspace can't represent all of the colors.
Where this is really going to come in handy is for super-wide gamut monitors for artists to do things like photo correction and and soft proofing
Now that the leading inkjet manufacturers have dot placement that's arbitrarily small with respect to bleed on even the best inkjet papers (5760 DPI & better), and they have dot size that's arbitrarily small for creating smooth gradients (1.5 picoliter), they've decided to start going after color gamut. With the new small droplet size, Epson didn't need light cyan, light magenta, and grey to acheive smooth tones anymore on the R800, so they added Blue & Red to the CMYK inks.
Previously, most high-end monitors encompassed almost the entire CMYK printable color space, lacking only a few extreme cyans and magentas. But soon, we will need these extended gamut monitors to see all the colors we can print.
Can anyone tell me how to set my sig on Slashdot?
Not quite. The "step" issue is separate from the fact that the RGB gamut does not cover the visible gamut all the way. There are colors we can see that no amount of twiddling can *ever* get an RGB monitor to reproduce.
You are right that a digital RGB representation is discrete, not smooth, but there are colors "outside the grid," too. Pure yellow, for example.
Here's a nice link, again: clicky click
Okay, I'm a little confused... ever since elementary school, I was taught that the primary colors are Yellow, Blue, and Red. I guess since you can add Blue and Yellow to get green, you can subtract the 2 to derive yellow....but it just bothers me that my concept of primary colors are different from the new definition... is there a technical reason to use Green over Yellow?
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.
Does this mean that I can finally design a website using flourescent orange? What's the hex value of that? ;-)
The House Between - Original Sci-Fi Series
I'm glad to see they're upgrading the colour on displays, as I've always hated the weak saturation of the cyan/green colour in particular (much closer than you'd think to pale grey than actual cyan).
For those that want to cyan should look, try the 'Eclipse of Mars' illusion at this site.
Why OpalCalc is the best Windows calc
... and generally cause a lot of people who do image processing a hell of a lot of heartburn. most popular formats simply don't understand more than three spectra. new formats are talking about *five* spectra. that's a 66.667% increase in raw data to process. not so bad you say... until you realize that color information is hugely redundant. then there's the more sticky issue of how do we use our algorithms on this data, because they are often not colorspace neutral. what happens if i need algorithm x which works really well in, for example, HSV, but crappily in this new color space?
With the black mask used in high quality TVs, the gamut is already displayed in an RGBK color space, derived from the RGB signal. Until the signal includes separate color info, which it doesn't seem to need, these additional display color elements will merely reflect (pun intended ;) the difference between the "ideal" image signal info and the physical limitations of the display technology.
--
make install -not war
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.
Alternative coloUr models habe been around for a while
I think that this is the wrong solution to a very real problem. While I would agree that standard def tv could use some improvement, the problem does not lie in the representation of color. IMHO the main problem is resolution. I have seen plenty of digital RGB photos that can, for all intents and purposes, perfectly represent what they capture. The problem is that standard-def is at a pretty low res (480i IIRC). The solution would be to simply pump more data at higher resolutions, like 720p. just my 0.04
Why is it that all these new technologies that manage to 'enhance' existing data turn out to be bullshit?
If there was talk of some end to end process to capture the 'RGBCMY' data, then store, and reproduce it at the other end, I'd be convinced. But, I'm not, because they're creating the new data from nowhere, and you can't do that.
Like tinyurl, but one letter less! http://qurl.co.uk/
If you still aren't comfortable, then fine. Make it 420nm violet to be safe. All non-visually impaired people can see 420nm light, too.
Si la vida me da palo, yo la voy a soportar Si la vida me da palo, yo la voy a espabilar
While I won't dispute the wider gamut of the proposed 5- or 6-component color space, the system offers few benefits to already encoded content made for viewing on a narrow-gamut RGB device.
:)
Sony made a 4-component digital camera a while back, it had two green channels. The gamut of this camera was really nice, a baseball diamond shaped area far exceeding that the typical sRGB consumer cams.
Combine 4-component recording technology with the 6-component display technology mentioned in the article, and we should start to see some nice color. Until then, I think I'll hang on to my antique 3-tube CRT projection system.
To say that CMYK cancels RGB is a misunderstanding of the context. RGB is a color model. CMY(K) is another color model. RGBCMY is yet another color model. The "additiveness" is a way to describe how the coordinates of a color model contribute to the actual frequency spectrum and intensity of light. Accordingly, RGBCMY (or more appropriately, RYGCBM, sorted by spectrum frequency) is an additive model. The advantage is that finer spectrum prescence of the primary colors makes it easier to reproduce the visible spectrum of light by adding the primary colors on top of each other.
Your remark on LCD using CMYk approach is also misleading. It is true that LCD masks out light coming from a white light source, but the resulting light, being in RGB primaries, still "adds up" to reproduce color. If you don't believe me, you can do a little experiment. Just spill some droplets of water on the screen, and watch the enlarged subpixels.
I once had a signature.
What you (and the page you referred to) call the C.I.E. colorspace is actually the CIEXYZ colorspace. CIE has defined many different colorspaces, so there's not one "CIE" colorspace. There are CIEXYZ, CIELAB, and CIELUV colorspaces for instance, to name a few.
And technically the images shown on that page you linked to are x-y chromaticities, which are computed from the X,Y,Z coordinates as
x = X/(X+Y+Z)
y = Y/(X+Y+Z)
which just gives you a handy way to look at colors in an easier to grasp 2D format. In reality gamuts are 3D volumes, but 2D pictures of those 3D volumes are difficult to make sense of.
Finally, the CIEXYZ colorspace is not any better than RGB at helping determine the perceptual distance between two colors. For that you need to use CIELAB or CIELUV.
Is there any particular reason why no one came out with this sooner? Seems pretty straight forward.
Mitsubishi HD rear projection televisions have already had this feature for over a year. I should know...I own one. Move on, nothing to see here....
Well, I think I should have all my comments modded as -5 idiot.
As many of you have pointed out, My momma must have dropped me on my head when I was a child.
I was wrong with the statments that I made. I was purely thinking of the "painter" analogy, and not the "flashlight".
Sorry, please feel free to delete this thread.
I am an idiot.
"The price good men pay for indifference to public affairs is to be ruled by evil men." ~Plato (427-347 BC)
...as a matter of fact, it is quite irrational to say, that it will deliver a better quality of the hi-res images, especially thouse ones requiring high ``detailization'', than the that the vector display technology.
Human perception of color is all based on having three types of cone in the retina: Cones that are sensitive to red, green and blue. Color is percieved as a ratio of those primaries. The eye can't tell the difference between equal amounts of red and green, and a single wavelength yellow light.
Heck, take a look at their "color craze" diagram. Making their RGB primaries more saturated would do more to improve the color gamut than adding additional wavelengths.
That said, for those with abnormal color perception, like some forms of color blindness, additional primaries that line up better with their peak sensitivities might make television appear more like how they percieve color in the real world.
What do you mean, a basis set? A set of colours from which you can derive other colours? For this kind of discussion, we need to talk primaries. As far as I am aware, negative colours in RGB space were introduced with sRGB, in an attempt to introduce a consumer "standardised" RGB colour space that would map to the gamuts of a wide variety of consumer display devices easily and with a minimum of development cost. The real issue is mainly about how widely spaced the primaries are in CIE1932/CIE1976/SML/Macleod-Boynton space (or some other physiological colour space). If the primaries are so close together that another device can be more red than your maximum red, or less blue than your minimum blue, then negative colours are perfectly acceptable - but only in terms of some other display device. The farther apart the primaries are, the larger the gamut, and better the display. More primaries can make a larger gamut, if the new primaries are outside of the gamut formed by the original primaries.
With the unfortunate problem that the datasets used to construct the CIE colour spaces are wrong. Well, not wrong, exactly, but they were created using data from experiments performed in 1924 on a small number of elderly pensioners. (Or so I am led to believe). The result of this is that the CIE colour spaces are a bit off towards the blue end. (This is because as you age, your lenses yellow as you gradually develop cateracts brought on by UV light - this absorption of low wavelengths has affected the data, making it less representative for the average joe-in-the-street than it might have been.)
Yet another invention that those of us who are colorblind can't use.
My eyes take three samples from the spectrum (well, four techincally, but the forth one covers a wide band that gets stimulated by all the visible colors, so it doesn't help determine hue.)
Until my biology changes, why should I care that the film I'm watching has, in addition to those three colors, three other colors in-between them? I'll see the same color whether it's a glowing magenta phosphor on the screen or it's a pair of a glowing red and glowing blue phosphors.
The only way I could see this being helpful is if different individual human eyes have different properties for their cones. Perhaps my red receptor gets peak stimulation at a frequency that's a bit off from where yours does, and therefore it isn't possible to construct a video monitor that correctly stimulates both my eyes' red receptors and yours. If that sort of thing is really common, then any technology that simulates the whole spectrum better would help (because the RGB system is dependant on everyone's eyes working the same way, with the same exact hot spots.) But if that's the reason for this, then there's nothing special about picking CMY other than those mark the halfway points betwen R,G, and B (the fact that they are the subtractive primary colors doesn't matter), and thus you have 6 samples instead of three. But again, if that's the case, then there is nothing special about adding exactly three more colors for a total of 6. Having 7, or 8, or 10, or 40 colors would be helpful too - the more colors the better the chance that it would work on anyone's eyes even if they are off from other people's.
Don't label something "offtopic" unless you know the topic well enough to tell what's on topic.
Ha ha... very perceptive; wish I had some mod points.
How far should we take the "full spectrum" above the visible range?
"Coming soon on the Discovery Channel! It's... Radiation Week!"
Trailer shows clips of an atomic explosion, inside a nuclear reactor, someone getting an X-ray, and so on.
Discovery Channel sued into oblivion after several thousand "SuperSpectrum" TV owners die from fatal overdoses of gamma radiation whilst watching this.
"Slashdot - News and Chat Sites Deviant". (Click "homepage" link above for details).
a linear combination of RGB can express any color in the universe.
Yes and no. In a strict mathematical sense, since we have three color photoreceptors, so percievable color space is three dimensional.
But in translating from the percievable color to RGB you find that some colors would have to use negative RGB components to be reproduced. Since there does not exist a display that can show "minus green," we compensate by using additional primaries.
That's not even touching the fact that under certain lighting conditions, rods act as a fourth receptor giving a four dimensional percievable colorspace. Did you ever wonder why some colors seem to stand out from sunset to dusk? Now you know the rest of the story...
I have a positive modifier on Troll. When I mod someone Troll their karma should go UP!
For those of you who are arguing that RGB is the be-all and end all, this page might give you a hint of what the real world is like.
:)
In particular the RGB vs CMKY color spectrum diagram, as you can see the RGB trangle is a sharp one, and cuts off many of the colors which add to the vibrance of pictures in the Cyan Yellow and Magenta regions. CMYK however also has it's failings, by combining these two they hope to push the envelope over a bit more of the visable spectrum. Pantone is given in the diagram as a reference, that's practically every color you'd ever want to see
The Irodori system from Japan was displayed at SIGGRAPH this year. They also have a 6-color system, but rather than adding CYM to RGB, they chose 6 new colors that trace the edge of the visible color gamut. They can display almost the entire visible gamut (as opposed to the one referenced in the article, which still leaves out large chunks).
Their hardware is 2 stacked LCD projectors, focused on the same screen, but with special filters instead of the standard RGB ones. It really has to be seen to be believed; one problem with this technology is that none of the promotional literature can possibly look as good as the actual product!
They also have software that can use the fancy hardware. Not only did they have a demo video (which implies a data format and corresponding player), they demonstrated a paint program where you can grab any of the fancy new colors and paint with it. They had stills of flowers, butterflies, and sports cars in violet, crimson, fuscia, and blue-green that you've never seen outside of real life -- they made conventional video and printed promotionals look sick by comparison...
doesn't sound like a good idea to me. dsp is already convoluted having to work on 3 seperate channels. also the space is not very efficient.. more than one way to make a single color is just waste.
what would be interesting is native support for a single wavelength channel. that would ensure that whatever precision is used (16bit, 32bit etc) available colors are evenly distributed among the visible spectrum. also, lookup tables could be used to convert the wavelength to different color spaces instead of proprietary lossy floating point routines.
bite my glorious golden ass.
Here's the actual research outfit working on the IRODORI system. It's a complete end-to-end system that includes cameras, front and rear projection systems and LCD displays:
Experimental System
I've seen it-- they're getting quite a bit more of the CIE color space than we're use to with traditional RGB displays, and the results show it if you get to actually see one (I have). The results are truly stunning...
The theaters need more reasons to get people out of their comfy chair and into the theaters and charge more money doing it. A couple of "showcase" movies that really show off the difference could do it-- some of these multispectral systems can exceed the gamut and dynamic range of film, and really underscore the fact that we've been seeing a narrower range of colors in reproductions for so long that we're used to it.
And of course, the same movies can still be "gamut-reduced" to RGB for DVD releases after the fact, so it may not really be all that expensive a proposition for them, considering many of them are already considering moving to digital projection as it is...
you totaly FAILED!
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.
The 6-color thing is really only used to increase the *size* of the color space; you still only need 3 values to specify the color. Many standard formats (e.g., TIFF) already have the ability to represent colors in the XYZ color basis instead of RGB, which can represent any visible color whatsoever.
This would be true if the blend of RGB colors actually created the destination color, instead of just our eyes 'blending' the 3 RGB colors that are close together.
If your monitor could *actually* show Magenta instead of having to blend red and blue to do it, that magenta color will look 'better'.
It's the same idea with multi-color printing. Sure, you can mix any colors with CMYK, but there are 7- or 8- or 10- or 20- color printing devices that contain exact-color inks, instead of a blend of inks to get the destination colors. This yields better printed colors.
While monitors and light are a bit different, it's the same idea.
color perception is a learned phenomena--bright, primary colors are more easily perceived, which is why they are popular with small children and sports teams;> while color is a universal phenomenon, our individual perceptions of it vary, depending on our physiological and sociological and cultural development (eg some primitive societies only identify 3 colors--black, white and red)
individuallly speaking, color perception is also relative--we rarely experience a single color, but many different colors all at once--it has been proven, starting with M. Chevruel in the 19th century, that perception of color(s) are influenced by neighboring colors--for example, a red object on a neutral gray background will cause the viewer to perceive a bluish cast on the gray!
the brain also employs some precognitive tricks to aid in perception--for instance, an object can be perceived as 'white' even in a low light situation, due to this compensation-- furthermore, color is influenced by atmospheric/volume conditions (eg the 'color' of a swimming pool), as well as surface texture and refraction effects...
also, as has been noted by many here today, transmissive (RGB) colors are additive, and therefore much brighter than reflective (CMY) colors, and contain a larger gamut (cmy does have some colors that rgb does not, but relatively few)
to counter some of the claims made by other posters, the human brain cannot distinguish between a 'pure' ie. spectral color, and a tri-color representation of said color (unfortunately, i'm away from my studio today, so i can't give more detailed references to back up my points)
and, to those who'd like to expand to a 6-color system, while this has its advantages, it also has its disadvantages, namely in color definition--in an RGB system, each color has one and only one RGB value, while in a CMYK system (in printing, K, or black, has to be added because CMY adds up to muddy brown) means that a color can often be defined in more than one color combination, which can lead to other problems (ask the printing world!)
ultimately 'good color' in consumer electronics is usually due to increased contrast and brightness/saturation of colors, not accurate reproduction of colors, because the goal isn't really to reproduce reality, but to create a vivid impression on the brain!
so, despite the breathless headline and PR, the 'revolution' here is more akin to the inkjet printers of the world adding additional colors to extend the CMYK gamut--an advance, but not a breakthrough...
The IEEE article mentions yellow and cyan but not magenta.
RGB is a set of orthogonal colors, and a linear combination of RGB can express any color in the universe.
Nope. The idea behind RGB was that RGB could express any color that we could perceive, which is quite a different statement. If you're near San Francisco, there is (or used to be) an exhibit in the Exploratorium that demonstrates this: two orange samples, but a prism shows a single wave for one while it breaks the other into two waves. We percieve both as the same shade of orange, but the prism shows us that we're wrong: there is a difference.
But the RGB concept is still flawed. Basically, from what I understand, the color receptors in the eyes don't respond to single wavelengths. They respond in different degrees to different wavelengths. That is, the "red" receptor has a response curve that peaks at red, but still has non-zero responses along a good deal of the visible spectrum. If it were otherwise, how could we see the "pure" orange sample?
Prior to transmission, the analog RGB signal is converted into the digital YCbCr signal....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.
Now you're talking about spacial resolution, when we're discussing spectral resolution. You're also talking about HD only... NTSC doesn't necessarily use CbCr. The production components may, but the broadcast signal is based differently. It uses hue and saturation, sometimes combined into a single AC chroma signal with hue as the phase and saturation as the amplitude.
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.
If you wanted to do that, you could just use a trilinear filter, or any other antialiasing technique, in RGB. You could do that in the TV's software, and not have to involve CMY. In fact, since VGA's resolution in luna and chroma are the same, any movie player on your computer has to "fill in" the missing chroma information anyway. So do TVs, but it's after the signal-processing step. This is all stuff you can do in software, without the expensive step of laying down CMY phosphors, increasing phosphor density and manufacturing costs.
There is quite a bit of arguing going on regarding expanding the color space to see a higher quality image. This is very similar to arguments regarding Color vs. B&W Television from an era in the past (or the same said about Color vs. B&W movies).
/.
Ideally, if you could, you would want to have a pixel that you could "tune" to a specific frequency and intensity, giving you a full range of colors from near infared to light just into ultraviolet.
To give an idea of what you could see from a system like this, go see a rainbow (a real one, not just a picture), and try to look at the blue/violet edge. This color, true violet, is something that you could never see on the best monitor, unless you have pixels or phosphors that will emit this color of light. No matter how hard you try to mix the RGB pallet, you will always end up with a washed out magenta trying to capture this color and will fail.
Indeed, I think this is exactly where this group is going to fail. Adding Yellow, Magenta, and Cyan will help fill the middle of spectrum, but will not improve the ends where current technologies don't cover the EM band of visible light at all.
Rather than trying to talk about the XYZ color coordinates, instead you need to think of the light you see as a two-dimensional graph with two axes, frequency on the horizontal and intensity along the vertical (just to "standardize" the format). Each "color" would have a different graph on this sort of diagram. When you are working with each color in a color space, you need to think of them being the same as the slider buttons on a sound equilzer, or a tone generator that has hundreds of sliders to "tune" to a given frequency. In this respect there is no difference between light frequencies and audio frequencies, other than you ear can "hear" a much larger range of frequencies than your eye can distinguish visible light frequencies.
The whole problem is that moving from that ideal pixel that could create a random "graph" of a color in the EM visible light spectrum, you instead have to deal with light emitters (or absorbers for print material) that have a very rough bandwidth limits to makes something close to that graph.
What is killing me in this reply is that I need to add graphs and diagrams to fully explain this, and I hope that you can understand what I'm discussing without them, unfortunately. This is just a limitation of
If you could get something close to that ideal pixel, with a more full spectrum view of a stored image and then compare it to an ordinary RGB image on a comparable device of the same brightness, the difference would be like listening to music on AM Radio vs. a audio CD. Until you see the difference you wouldn't know what you were missing. Also, some people perceive color differently than others, with the rods and cones (they do work together for color perception, even though the work they do is slightly different) of each person picking up slightly different frequencies better than others. People with tetra-chromatic eyes (there are some people with this ability to see 4 colors...usually women) would spot this even quicker than us mere mortals. "Color blind" people would be as impressed with this system as tone deaf people are with good music.
As for your colour space stuff, plenty of people have already put you right; and I would back them up: I spent ten years designing broadcast video equipment that works in the YCbCr domain, and it's quite easy to generate so-called "illegal colours" that cannot be properly shown on an RGB device; notably the muddy dark green and lurid pink-purple that result from a data stream of all zeroes or all ones respectively.
Cb/Cr subsampling is not all that noticeable and is not a problem unless you intend to post-process the pixels.
Uncompressed digital Y'CbCr video can look really good. The major problems for TV consumers are MPEG-2 compression, 8-bit quantization artifacts, and poor displays.
Really, RGB only really works because it's a close match to the 3 colours our eyes are sensitive to.
For all intents and purposes, that means that it works about as well as it can.
Since the human eye reacts to a range of colors, with a nice peak at RGB, and tapers off in a nice fashion, we can't tell the difference between yellow and the appropriate levels of red and green, because they both have the same reaction on our eyes.
With your case of going higher frequency than the blue cones, all we see is a dimmer blue, we can't actually perceive that as a "more violet" blue, unless the eye actually reacts differently to higher frequency blues than lower frequency blues in the blue cones.
Which, as far as I know (and I may be mistaken), isn't the case. It's not as simplistic as something like a 3 band graphic equalizer display, but it's not that far off, either.
Yes, and no trickery on playback can restore the unique detail that's been lost in the encoding. All that an improved playback technology can do is display more of the gamut that is represented on the input. It cannot compensate for information lost during generation of the signal.
>Uncompressed digital Y'CbCr video can look really good.
It DOES look really good, as it seems you know. And HD looks stunning. But it's a shame that due to the
>MPEG-2 compression, 8-bit quantization artifacts, and poor displays
only people working in TV studios and equipment manufacturers ever get to see it as it should be. If the broadcasters only upped the bitrates by 50% it would be something. Doubled would be even better. But then you'd only be able to sell half the advertising space, wouldn't you?
Current digital TV is the video equivalent of a 128kbps MP3, if not worse.
I think that is incorrect. What we call color is the frequency of an electromagnetic wave (aka "light"). Our eyes have detectors for four of these frequencies, that we call "red", "green", "blue", and "white" (white is detected by the rods, the colors by the cones).
In reality, there is an infinite number of colors. Note that infrared and UV are also colors under that definition; the only reason we don't normally think of them as colors is that our sense can't perceive them. Other than that, there is nothing fundamentally different between them and normal colors (which is why you shouldn't be too surprised when come digital cameras actually "see" infrared light). Which combination of R, G and B gives you infrared, exactly?
So it is true that if you had a 4D color space display (RGBW for red, green, blue and white) you could calibrate it to one person so that the display can accurately show any color that that person can see (people's cones do not always react to exactly the same frequencies, which can explain some interesting miscommunications. And let's not go into the few people who have an extra 4th color cone). Anyways, that display could show any color you can see, but it still wouldn't be able to show every color that exists. That's the difference.
The technicality here is that the R G and B frequencies don't line up (and scale) in line with the human eye. If a better set of frequencies/scales was chosen, then we'd be able to see any color as a compilation of the R, G and B receptors in the eye.
This is gleaned from your linked-to article, aside from the whole bit about negative response, which really makes no sense at all. Perhaps a failing on my part, but it's not at all obvious how to properly display a 500nm color we need to have a negative amount of 625nm red.
And in comparing their sensitivity charts vs. their primary values necessary charts it seems like they've chosen the wrong primary colors to use for RGB, and that an appropriate one may exist that will do better (or not, I'm not a scientist at this, but as a photographer, I'm very curious in this area).
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
...until I see pictures proving the difference... Oh, wait...
...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.
Although the meaning of colors like #70809E are quite strictly defined in web standards (they are sRGB colors, I believe), in reality such colors are rarely displayed accurately on real monitors with ordinary software. What if your monitors have significantly different color temperature (so the same sRGB color appears warmer on one monitor than another) or gamma settings (so the brightness of #808080 relative to #ffffff are different)? On my monitor, both are tunable.
Indeed, with a number of primary colors (which must lie in the horseshoe shape), one can only produce the colors lying in their convex closure, which is the smallest polygon containing all the points corresponding to the primary colors. Since the horseshoe shape is not a polygon, it is impossible to produce all human-observable colors by mixing a finite number of primary colors.
I couldn't see this info elsewhere. I was at a colour course at Siggraph 2004 last Sunday for most of the day (8:30am to 5:30pm on just colour!). I also got to see both the IRODORI wide gamut display and the HDR display, both were very cool. Once we get HDTV it is clear we can go at least one more step.
l i/material /notes/Chap3/Chap3.3/Chap3.3.html
m ma/Colo rFAQ.html
The problem with RGB is it can't describe all colours the eye can see. This was a problem for the guys that made Salem Cigarettes. The problem is their brand's colour lies outside of the small RGB gamut! The best they can display for their brand in RGB is only an approximization. Sure it is a blue-ish green-ish colour when you see it on TV, but it isn't what you would actually see in reality or with a wide gamut colour device. They weren't the only company with this problem.
This is a huge problem for hundreds of thousands of people every day. There are colours that exist that they can't see in their work. They can sit down on a computer and work in an alternative colour space such as L*a*b* and create these colours and even print these colours, but thanks to our RGB monitors they can't view them! What do they do when they have to print an add for Salem Cigarettes? Guess and check I suppose...
Technically RGB can represent more colours than we give it credit for, you just have to allow for negative values which is only useful mathematically until we invent anti-photons to remove light...
Here is a short link to make explain details:
http://www.cs.sfu.ca/CourseCentral/365/
A few more things I'll add from that course; HVS is basically the worst colour space and CIELAB or L*a*b* is the best. CYMK is technically multiplicitive, not subtractive like so many people like to call it. Our eyes are sensitive to short, medium, and long wavelengths, not Red/Green/Blue. RGB happens to mostly match up with what we percive, but it is an over simplification.
For the real keeners here is a nice FAQ about this:
http://www.poynton.com/notes/colour_and_ga
The only thing I have said about DSP is that in order to sample a high frequency a sampling frequency of at least double that is needed to properly record it. If this is so wrong, then please stop posting AC and tell me what is wrong about it... A whole book is not necessary. If you can't/won't tell me then stop posting.
As for the rest of my post, it deals only with how higher frequency (individually inaudible sounds) can interfere to produce sounds we can hear (or to make this more simple for you even a tone that is audible and a tone that is inaudible can interfere to produce a 3rd audible tone... this IS how heterodyning works and is a method used to hear the sounds a bat makes by shifting it to an audible set of tones... these tones are not made up of just audible tones... they are made up of an inaudible set of tones interfering with an audible tone. The shifted tones may even be simulated by frequencies within the normal hearing range if you so wish to do that, but the quality is different if simulated rather than heterodyned to an audible range... it's just not the same.
Before you start spouting off more about human biology there is a lot that is not known about how the human brain interprets the different stimulii applied to the nerves in the ear.
And no, heterodying and superheterodyning are not methods just used for electromagnetic frequency shifting... the term is used for any frequency shifting in the manner I mentioned.
I had no idea there wasn't one CIE colors space... Thank you.
Assuming that you are not a mutant, you simply cannot hear a frequency that is higher than 20kHz. It is impossible because of the way the human ear transforms soundwaves into neural stimulation. Because of the way the human ear is "built", it acts as a band pass filter. Slashdot really isn't the place to explain this in detail. If you don't believe me, look it up in a book. You're not going to get any wiser if you reject recorded science as a source of information.
The result of mixing inaudible frequencies may well be an audible sound, but that sound can be captured exactly in the range below 20kHz, ignoring the higher frequencies. All you need is a low pass filter, like the human ear (A band pass is a low pass and a high pass combined, the important part regarding sampling is the low pass.) That, after all, is the reason why you do hear the sound, so there is no error in replicating this process with technology. If you did as suggested and got a book about signal processing, you would know that a low pass filter is mandatory before sampling or you're bound to get aliasing artifacts. This low pass filter is the reason why, in the frequency domain, a signal appears below 20kHz when the original signal only had components above 20kHz. It is the very same reason that explains your ability to hear the tone. I hope I have stressed the similarity of the pre-sampling low-pass-filter to the way the human ear works enough to make you remember it.
One thing we DO know about the human ear is that it is a frequency domain sensor. You do not hear waveforms, but frequency intensities over time. It is important to note that this is independent of psychoacoustics. What our brain makes of the signals which the ear produces is of no concern regarding the way the sensor itself works. What the ear can't sense, the brain cannot perceive.
To make an analogy to the topic of this thread: Humans can't tell if light is a mixture of two pure (single wavelength) colors or some other two pure colors which produce the same stimulation of the color receptors. The CIE chromaticity diagram shows you which combinations of pure colors are indistinguishable, IOW the SAME color to us, even though they are physically distinct. It would be foolish to say that you need to record the full spectrum in order to accurately reproduce visual appearance. Instead you only need to record what makes a difference to the sensors through which our brain perceives the world. It is similarly foolish to say that you need to record all air pressure changes in order to accurately reproduce sound. If the ear can't transform it into neural stimulation, you don't have to record it. It is that simple.
I'm going to patent adding K to RGBCMY screens! And maybe white? Hmm... What will I do with all the money I make?
You're certainly right about it being non-obvious. It took me a while to wrap my head around it, too.
The problem isn't that they've chosen the wrong primaries, although you're right that a different set could cover better than the ones we're using. The problem is that the three types of color sensors in the eye are not perfect single-frequency sensors-- they have wide, irregular frequency responses that overlap significantly. There are some spots where all three receptors would fire from a single-frequency beam of light, notably around 450-475, looking at the chart. How can you represent a different blue with a blue in that part of the spectrum if it fires the red (and/or green) receptors? It will inevitably look purple. The "negative" amount of red is just a mathematical artifact, a way to say "to represent this blue, you'd need a negative amount of red to cancel the phantom red caused by the blue light"-- and you simply can't do that in real life. As a photographer, you may have noticed effects like this occasionally in photographs. I have a shot of a beautiful deep blue flower I took in Arizona that is a crappy purple color in every shot I took. The film or CCD (both are RGB) you use to capture the image will produce the occasional noticable color distortion.
It's because of this overlap that we can't pick just three primaries that cover all the colors we can see. If the peaks were non-overlapping, it would work much, much better. So we need more complex models with nonlinear color mapping functions like CIE XYZ or CIE L*a*b to fully exploit the potential of the overlapping wide-response receptors in our eyes.
It is difficult to show with nothing but an RGB computer monitor, since it can't display the colors it can't display, but you might be able to find a Pantone book somewhere and look up some colors that are out of gamut for RGB displays, scan them or take a picture, and then look at the difference on your screen. You've probably noticed a similar effect when you try to print color images, as well, since color printing is CMYK, and not all RGB colors are in the gamut for CMYK.
We use everything from radio waves to x-rays in appliances these days. With a dynamic range spanning so many orders of magnitude, how could it possibly make sense to talk about a percent difference? How about orders of magnitude different? I'm not saying it's mathematically impossible to have a percentage of a wavelength, but it's pointless.
All right. I pick wavelengths 350nm-750nm. And we'd be looking at the damage done to human skin cells over that range. There is a threshold, and it is significant. Just like if I hike 10km on a trail to the top of a cliff--one more meter would be a very small percentage of the hike, but with significant consequences. Somewhere between 350nm and 420nm is a cutoff for normal human skin: lower wavelengths cause damage, higher wavelengths are harmless. Just like a body temperature of 37C is normal, but only a couple of degrees difference can cause brain damage / death.Si la vida me da palo, yo la voy a soportar Si la vida me da palo, yo la voy a espabilar
Yes, however, a microphone does detect the overall waveform and does not split it up into frequency components. This will result in the distortion of the audible tone when recorded at a sampling rate that is below the two frequencies that make it.
If you do record at higher sampling rates you can increase your low pass filter and avoid aliasing effects until you reach about half of your sampling rate. This distorted sound, when replayed will not sound like the original tone as you would have heard with your ear. It will be close to the same tone, but it won't be the same.
There has been much debate as to whether or not including these higher frequencies in recording adds to music. Some people claim it does, others claim it doesn't. For me the quality between a 44.1kHz recording and a 96kHz recording is extremely dramatic.
MS buys out Genoa Color Technologies!
Gates: "Now I can make better looking Windows OS..grunt...grunt...hehehe"
Thanks for the civilized discussion. Some folks like to resort to personal attacks and such. I'm glad you didn't.
Si la vida me da palo, yo la voy a soportar Si la vida me da palo, yo la voy a espabilar
K stands for key. it was traditionally the reference color (plate) used to register (align) the other process colors in offset printing.