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This article is fairly technical. I think the introduction should be expanded with a brief explanation of how color spaces are actually used by artists and graphic designers today, i.e. what problems they solve. In particular, laypersons are now exposed to color space terminology via popular PC software such as Adobe Photoshop, and these readers are probably more interested in "What is it and how is it useful?" than "How was it developed?". 151.199.131.100 11:47, 15 July 2006 (UTC)
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I agree. I could understand nothing from it.
I'm not sure what to do about this, but I think it important to mention that there are older systems, particularly the Mussell (Hue, Value, Chroma) system which predates nearly all of the other systems and, IIRC, was designed for painters to be able to talk more accurately about the paint colors they wanted.
LAB, is another popular color space, which should be mentioned. I used to work on a research project to match dental porcelain colors to actual tooth colors, and I had to write a program to calculate color differences. The LAB system is perceptually equalized so that the color differences are quantifiable, but it is nearly impossible to think in the LAB system. On the other hand it's pretty easy to visualize the proper color once you know it's Hue, Value and Chroma, so products are generally sold by Munsell color, but the Munsell system is not perceptually equalized because the color difference between one hew and another is arbitrary, so I had to convert everything over to LAB before any calculations could be done.
My point here, is that there is lots of important information about Color Spaces which has nothing to do with RGB, or CMYK. In particular, I think the notion of regular and irregular color spaces ought to be included somehow. On the other hand I did this work a long time ago (when I was 16) so my memory is a little fuzzy, and I have no references immediately available on the subject. MRC
From the article:
From the article:
I've been working a bit on the HSV color space page. Maveric brought up an interesting point; should we be making the distinction between a color model and a color space? As I understand it, (someone correct me if I'm wrong) the color space is the region of possible colors that is described by a particular color model. Color models would include RGB, CMYK, and so on, but sometimes, two different color models will describe the same color space (such as HSV and RGB). Or would the term gamut be more appropriate to describe the collection of possible colors defined by a color space?
I found colors can be represented in Stokes vector.
Is there any identical color model to this Stokes vector form?
The parameters of HSB are same that of partialy polalized light.
Hue is represented in [0 - PI] in Stokes vector, not [0 - 2PI].
Stokes vector form of color is very useful for color transform. For example, hue rotation is performed by just a matrix product. -- goto
Reviving the old question above: We should really try to be clear, in all color-related articles, on the difference between color space and color model, if indeed there is such a distinction. The terms seem to be used interchangeably; the article as it currently stands makes a fairly good distinction between them, but confusion could result, especially since the article begins with a definition of color model, rather than color space (and even more confusingly, because color model [used to] redirect to color space).
Additionally, there are problems such as Lab color space opening with "CIE L*a*b (CIELAB) is the most complete color model used conventionally...", odd because it does not say "The Lab color space is..." and because it does say "...is [a] color model." And of course, there are these:
Etc. Anyway, this could probably use some clarification across all the color articles. -- Wapcaplet 19:42, 5 Mar 2004 (UTC)
I like the work you've done to this article - bravo! I'm not so sure I like the idea of having a separate model/space article for each model/space. Though, having either one redirect to the other could just cause more confusion, so maybe it is good to keep 'em separate. It just doesn't seem like there'd be much to say about XYZ color space, aside from the fact that it's defined by the XYZ color model. It's about time we had an article on gamut though (which is looking really good!). Dunno if I'm ready to dive in and clean all these up yet either... but hopefully we can get the ball rolling. -- Wapcaplet 01:13, 6 Mar 2004 (UTC)
I think I may have been unclear; what I meant was that I am not sure I see the benefit of having both RGB color space and RGB color model, for instance (at the risk of contradicting my earlier statement that the two concepts should be made distinct). Certainly, I agree that each color system---RGB, CMYK, HSV, etc.---should have its own article, as there is a lot to say about each. I fear that having both RGB color space and RGB color model risks a lot of unnecessary duplication, since the two subjects are so closely related; perhaps a title such as RGB color system or just plain RGB might be better, as it avoids the problem with "space" and "model" being subtly different; the distinction between "space" and "model" can then be made in (I hope) a more neutrally-titled article, if such a distinction is necessary for that article.
Whether there should be a separate color model article, I don't know. I'm fairly sure you know more about it than I do, so your input on that would be good. -- Wapcaplet 02:50, 6 Mar 2004 (UTC)
Valid points. I never really considered that there are many different RGB and CMYK color spaces. I suppose the same would be true of other color spaces as well; would it be true to say that a color space is influenced not only by the corresponding color model, but also by the environmental conditions (lighting) and properties of the output device (printing inks, monitor phosphors)?
I agree with having RGB color model as a main article, and RGB color space as a more detailed discussion of RGB color spaces. For most color models, it won't be necessary (not as of now, at least) to have a separate color space article, so those should be unified into the main HSV/YUV/CIE color model articles until there's a need to split them off. I agree that color space should remain a single article, unless there becomes a strong need to have a separate color model article. (Or should the main article be color model instead of color space?)
We are making progress, I think :-) -- Wapcaplet 16:19, 6 Mar 2004 (UTC)
The following paragraph is too RGB-specific for this general article, I think.
The RGB color model can be implemented in various specific incarnations, depending on the capabilities of the system used. By far the most common general use incarnation at the time of this writing is the 24 bit implementation, with 8 bits per channel. That means that each of the three channels in such an RGB implementation can store 256 discrete levels of color. Any color space based on the RGB model is thus limited to a gamut of 256×256×256=16.7 million colors. Therefore a "small", "restrictive" color space based on this RGB implementation will result in exactly the same number of colors as a "large", "generous" space. The only difference between the two is the volume their gamut cover, but that is always inverse proportional to its density on the reference space.
Smyth 12:23, 31 Aug 2004 (UTC)
I hope I haven't clashed with any work in progress by adding to the sRGB and Pantone artices, and adding every color space I could find to the Color space category. I didn't see this discussion until just now. Also: is there a discussion of ICC profiles anywhere? Notinasnaid 16:21, 31 Aug 2004 (UTC)
"An implementation which uses 16 bits per component will result in exactly the same range of colors as the 8 bit version, but to a 256×256×256 ≈ 16.7 million times higher accuracy."
This is surely wrong. Is 16 bit/channel RGB 16 million times more accurate than 16 bit/channel greyscale, and is 16/channel bit CMYK 256 times more accurate than 16 bit RGB? No, surely not. On the other hand this replaced a section that said "twice as much" accuracy, and that's clearly wrong too. (Analogy: if you double the number of decimal places you do much more than double the accuracy of a number).
It might be safest just to say "substantially higher accuracy". Thoughts? Notinasnaid 09:23, 4 Feb 2005 (UTC)
Much better. On reflection I think the original (not gone) phrasing was seeking 'precision' rather than 'accuracy'; and the precision is 256 times. Notinasnaid 22:09, 4 Feb 2005 (UTC)
It was said "It just doesn't seem like there'd be much to say about XYZ color space, aside from the fact that it's defined by the XYZ color model." Personally, I think it is very important that the CIE XYZ space is mentioned, as correct color space conversions are expressed as functions of XYZ coordinates of the spaces participating in the translation. I feel the following points are absent from the current article:
- linearity of color spaces, with proper notation ("prime" notation for non-linear spaces, such as Y'PbPr, and R'G'B' vs linear RGB)
- coordinates/definition of a color space (color primaries, white point)
- quantization and gamma correction, along with most commonly used gamma curves
- add more examples of color spaces - scRGB, explain "studio RGB" vs "computer RGB"
- clarify which Y'PbPr/Y'CbCr spaces are being referenced - ITU-R BT 601, BT 709, SMPTE 170M etc etc.
Lastly, it should be pointed out that the R'G'B' spaces currently used in computer graphics/video are, in fact, represented on 32 bits. Indeed, 24 bits are actually used for color channels, but ease of addressing and manipulation dictated a full double word is used. The remaining 8 bits are used for storing transparency information (alpha). 10 bit formats are emerging (A2R10B10G10).
I'm somewhat of a newbie to editing Wiki, and so I didn't think it was proper to proceed with these modifications prior to bringing them to attention in the discussion page. 08:11, 12 April 2006 (UTC) D.
A color space is multi-dimensional. A RGB color can thus be seen as a 3D object: Red=X, Green=Y, Blue=Z.
It needs to be pointed out that RGB, LAB, YIQ and HSV can be seen as 3D objects. An illustration of a 3D view of a colors space would make the concept much easier to understand! -- Kasper Hviid 12:14, 26 Feb 2005 (UTC)
I am unsure whether the article always uses "Color Model" as a word in itself, or whether its sometimes uses it as a synonymous for "Color Space".
In any case, the Color Model part needs to be stripped into a article on its own. However, I don't feel I have the knowledge to do this.
If I may quote from color management for photographers:
A color model is a method of grouping numeric values by a set of primaries. Most color models have three primary components (e.g., RGB, CMY, LCH, HSV, L*a*b*). Some application-specific color models use more components, for example, CMYK. Photoshop and other image editing applications work with multiple color models. Some scientific color models such as x,y,Y or L*a*b* encompass all of human vision and have a defined scale such that a particular color will always have the same set of values. It’s quite useful to be able to assign a numeric value to a color based upon how humans perceive colors. Other color models such as RGB or CMYK have no standard defined scale or reference. These color models are abstractions and cannot describe a specific color with out first defining the scale or reference. Having an RGB value such as R10/G30/B50 does not tell us how to reproduce that color; the values provided are simply a ratio of the primary components (in this case RGB) without a necessary scale. In this example we know there’s more blue than red, more green than red, but not as much green as blue. Without a scale to tell us the actual amounts we can’t reproduce this color. This is where a color space comes into play. A color space provides this additional and necessary information.
Think for a minute about the term color space. The first word, color, is fairly obvious. Let’s look at the term space in context. I have three sets of numbers to define red, green, and blue (R10/G130/B50) but how red or green or blue are these values? What is the scale? It is possible to plot any three primary values in three dimensions by treating the primaries as coordinates in space. This creates a solid or volume that represents all possible colors in that color space. This is a color space! The color space exists within the larger universe of human vision. Each color space is in a different position relative to this universe. Thus the same RGB values in each color space will be in a different location.
Going back to the chocolate chip cookie analogy, suppose a color model is a cookie recipe with only three ingredients. I give you this recipe, which simply calls for 1-flour, 8-butter and 2-chocolate chips. You don’t have enough information to make the cookies. However if I provide you the recipe with a specific scale—1 cup of flour, 8 tablespoons of butter, and 2 cups of chocolate chips—I’ve provided the necessary information, the scale, to make a dozen chocolate chip cookies. If I provide additional information such as the brand of chocolate chips, you can reproduce exactly the same cookies I made. I can give you the cookie recipe in the metric scale such as liters and grams and you can still makes the same cookies even though the numbers are different. A color space is a color model that has a known reference and scale, in this case primaries (the ingredients) and scale (specific quantities of these ingredients).
The image for subtractive color mixing seems too dark. Is this intentional? Otherwise, we could just make a negative of the additive mixing image and use that instead. - SharkD 08:11, 23 October 2006 (UTC)
Why is there absolutele no mention of the ISCC-NBS color model? -- Metallurgist 00:41, 15 November 2006 (UTC)
From the article:
However, a color model with no associated mapping function to an absolute color space is a more or less arbitrary color system with little connection to the requirements of any given application.
Cone Contrast Space if defined by the change in response of the three cone types. The origin of this space (0,0,0) is defined by the current state of adaptation of the three cone types, so it is certainly not absolute or arbitrary. And it is the most useful space to use if you want to model the visual system. Drichters 02:23, 23 February 2007 (UTC)
I have reverted the edit changing "reflected" to "remitted." While "remission" may be a term of art in spectroscopy, it is not generally used in color science. For example, the term "remission" does not appear in the index of Wyszecki and Stiles's second edition, a definitive reference in color science. Lovibond 16:22, 25 June 2007 (UTC)
I would just get rid of the list article and use this navigation template in all color space articles. It needs to be expanded, of course, but that's easy. I prefer navigation templates to "list of..." articles unless the meaning of each element in the list needs to be explained.-- Adoniscik ( talk) 04:07, 21 January 2008 (UTC)
The article mentions "pure colors" but doesn't give any information on what a pure colour is. —Preceding unsigned comment added by 203.214.49.35 ( talk) 08:08, 13 August 2009 (UTC)
"For example, although several specific color spaces are based on the RGB model, there is no such thing as the RGB color space."
Ok, this sentence contradicts with Wikipedia itself! http://en.wikipedia.org/wiki/RGB_color_space
Please, fix this guys. — Preceding unsigned comment added by Comptrol ( talk • contribs) 09:30, 30 June 2011 (UTC)
Section headers need improving. 188.223.18.19 ( talk) 02:28, 13 March 2012 (UTC)
Why does this article begin with a definition of 'color model'. It is not clear to me, a non-specialist, whether color model and color space can be used interchangeably, or if this is just poor article structure. I would have thought a page on color space should begin with an unambiguous definition of color space. 86.31.69.235 ( talk) 09:55, 31 May 2012 (UTC)
Does the "Real Color Wheel" deserve mention in this article? See: http://www.realcolorwheel.com/colorwheel.htm It seems to represent important work in defining an improved color space. Thanks! -- Lbeaumont ( talk) 14:10, 27 March 2014 (UTC)
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I propose that the two articles Gamut and Color space be merged considering the amount of overlap in their content. RenZut ↂ 11:05, 14 November 2017 (UTC)
Hello all, I'am searching around but I'am unable to find any article for color scale, colors scales, color scales. This item is important for cartography, datavisualization, scientific graphs., etc. There are rainbow scales, heat map scale, sequential scales/ gradiant scales/ color ramp, diverging scales, qualitative color scales (see example on colorbrewer2.org by Cynthia Brewer). Cynthia and others have written academic article more or less on it while treating about semiotics and color theory. Rainbow scales are known to be BAD ( source), etc. I'am checking up with you before to create the article : did any of you saw an article about color scales ? Yug (talk) 14:17, 12 May 2018 (UTC)
I just saw the notice put up to merge Draft:Color and mathematics into this. There is some good writing and explanation at Draft:Color and mathematics and an excellent "see also" list, and IMO it's not really a distinct topic. So a merge might be a good idea. North8000 ( talk) 17:45, 18 March 2019 (UTC)
This actually often creates some confusion (in code, and related technical documentations, discussions). They use "colorspace" to mean yuv2rgb matrices ("matrix coefficients")! While this article is somehow mainly about the "color primaries" concept in H.273! See ITU-T H.273. Hym3242 ( talk) 03:33, 13 March 2024 (UTC)