blocks|key|915810|text|纯色有波长(任何单色LED都有特定的波长)。红色、绿色和蓝色都有一个波长范围。但是，当您制作RGB颜色时，您将这些波长相加在一起，这不会得到新的波长。眼睛无法区分由一个波长组成的黄色和添加红色和绿色的黄色(眼睛是如何工作的)。我建议你多读色彩理论方面的书。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|915811|http://en.wikipedia.org/wiki/RGB_color_model|offset|length|915812|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|18|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@$D|O|E|P|1|Q]]|A|$]]|$1|F|3|-4|5|6|7|R|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|C]]]]

A pure color has a wavelength (any single color LED will have a specific wavelength).
Red, green and blue each have a range of wavelength. However, when you make an RGB color, you add these wavelengths together, which will NOT give you a new wavelength. The eye can't distinguish a yellow composed of one wavelength from that of adding red and green (just how the eye works).
I'd recommend reading up on color theory

<a href="http://en.wikipedia.org/wiki/RGB_color_model" rel="noreferrer">http://en.wikipedia.org/wiki/RGB_color_model</a>

blocks|key|915846|text|计算波长有点棘手，正如小精灵提到的，并不总是可行的(另一个例子是通过混合等量的红蓝光获得的颜色。紫色没有单一的波长)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|915847|但是，如果您想要做的是通过名称识别颜色，那么HSV模型将是一个很好的选择。HSV是色调(颜色在色轮周围)、饱和度(相对于黑/灰/白的阴影有多少颜色)和值(像素的亮度或暗度)。在这种情况下，色调可能正是您想要的。|915848|如果您使用的是.NET语言，那么您就走运了。请参阅Color.GetHue+Method，它为您完成了所有工作。|offset|length|915849|否则，请参阅HSV+at+Wikipedia了解更多详细信息。|915850|本质上，如果R、G和B是从0.0到1.0的浮点数(而不是从0到255的整数)，那么：|915851|M+=+max(R,+G,+B)
m+=+min(R,+G,+B)
C+=+M-m

if+M+=+m+then+H'+is+undefined+(The+pixel+is+some+shade+of+grey)
if+M+=+R+then+H'+=+(G-B)/C+mod+6
if+M+=+G+then+H'+=+(B-R)/C+%2B+2
if+M+=+B+then+H'+=+(R-G)/C+%2B+4|code-block|syntax|javascript|915852|在将RGB转换为HSV时，您可以将H‘乘以60度，但出于您的目的，H’可能也没问题。它将是一个从0到6(几乎)的浮点数。0为红色(与6相同)。1表示黄色，0到1之间的值在红色和黄色之间着色。所以0.5应该是橙色。重要的标志是：|915853|0+-+Red
1+-+Yellow
2+-+Green
3+-+Cyan
4+-+Blue
5+-+Purple
6+-+Red+(again)|915854|希望这能有所帮助。|915855|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/system.drawing.color.gethue%2528v=VS.90%2529.aspx|1|http://en.wikipedia.org/wiki/HSV_color_space#Hue_and_chroma^0|0|0|P|J|0|0|6|G|1|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|17|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|18|8|@]|9|@$F|19|G|1A|1|1B]]|A|$]]|$1|H|3|I|5|6|7|1C|8|@]|9|@$F|1D|G|1E|1|1F]]|A|$]]|$1|J|3|K|5|6|7|1G|8|@]|9|@]|A|$]]|$1|L|3|M|5|N|7|1H|8|@]|9|@]|A|$O|P]]|$1|Q|3|R|5|6|7|1I|8|@]|9|@]|A|$]]|$1|S|3|T|5|N|7|1J|8|@]|9|@]|A|$O|P]]|$1|U|3|V|5|6|7|1K|8|@]|9|@]|A|$]]|$1|W|3|-4|5|6|7|1L|8|@]|9|@]|A|$]]]|X|$Y|$5|Z|10|11|A|$12|13]]|14|$5|Z|10|11|A|$12|15]]]]

Working out wavelength is a bit tricky, and as Goblin mentioned, not always possible (another example is the colour obtained by mixing equal amounts of red and blue light. That purple has no single wavelength).

But if all you want to do is identify the colour by name, then the HSV model would be a good one to use. HSV is Hue (where the colour is around the colour wheel), Saturation (how much colour there is as opposed to being a shade of black/grey/white) and Value (how bright or dark the pixel is). In this case Hue is probably exactly what you want.

If you are using a .NET language, then you're in luck. See the <a href="http://msdn.microsoft.com/en-us/library/system.drawing.color.gethue%28v=VS.90%29.aspx" rel="noreferrer">Color.GetHue Method</a> which does all the work for you.

Otherwise, see <a href="http://en.wikipedia.org/wiki/HSV_color_space#Hue_and_chroma" rel="noreferrer">HSV at Wikipedia</a> for more details.

In essence, if you have R, G and B as floats ranging from 0.0 to 1.0 (instead of ints from 0 to 255 for example), then:

<pre><code>M = max(R, G, B)
m = min(R, G, B)
C = M-m

if M = m then H' is undefined (The pixel is some shade of grey)
if M = R then H' = (G-B)/C mod 6
if M = G then H' = (B-R)/C + 2
if M = B then H' = (R-G)/C + 4
</code></pre>

When converting RGB to HSV you then multiply H' by 60 degrees, but for your purposes H' is probably fine. It will be a float ranging from 0 to 6 (almost). 0 is Red (as is 6). 1 is Yellow, with values between 0 and 1 being shaded between Red and Yellow. So 0.5 would be Orange. The important landmarks are:

<pre><code>0 - Red
1 - Yellow
2 - Green
3 - Cyan
4 - Blue
5 - Purple
6 - Red (again)
</code></pre>

Hope that helps.

blocks|key|699726|text|http://en.wikipedia.org/wiki/Visible_spectrum|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|699727|这是可能的。请参见上面的。灰色背景显然让它变得更容易。你可能会自己得到这样的东西，甚至会改进它。但要准确地做到这一点，将花费大量资金。您将需要一位色度专家、一个校准的监视器和观察环境(因为像素的主要波长仅仅意味着在校准的观察环境中它在校准的监视器上近似的单色波长)。所有这些都将是几千美元。在维基百科上显示的上述链接所做的工作似乎不那么准确，但它可能是您想要的。|699728|entityMap|0|LINK|mutability|MUTABLE|url^0|0|19|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@$A|N|B|O|1|P]]|C|$]]|$1|D|3|E|5|6|7|Q|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|R|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|4]]]]

<a href="http://en.wikipedia.org/wiki/Visible_spectrum" rel="nofollow">http://en.wikipedia.org/wiki/Visible_spectrum</a>

It is possible. See above. Gray background apparently makes it easier. You might get something like that on your own, and even improve on it. But to do it accurately will cost major dollars. U will need a colorimetry expert, a calibrated monitor and viewing environment (since what the dominant wavelength of your pixel is just means what monochromatic wavelength it approximates on your calibrated monitor in your calibrated viewing environment). All this will be a few thousand dollars. The work done at the above link, shown on wikipedia, does not seem that accurate but it is probably what you want.

blocks|key|699802|text|只需将RGB转换为HSV，然后将HSV值转换为度，这就是答案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|699803|650+-+250+/+270+*+D|code-block|syntax|javascript|699804|其中D是度数。|699805|考虑到。|699806|紫色有380-450+nm的波长，蓝色有450-495+nm的波长，绿色有495-570+nm的波长，黄色有570-590+nm的波长，橙色有590-620+nm的波长，红色有620-750+nm的波长，然后你只需要检查它是否在这些范围内，然后你就可以对它进行分类了。希望这能有所帮助！|699807|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Just convert the RGB to HSV then get the HSV value to degrees and this is the answer:
<pre class="lang-py prettyprint-override"><code>650 - 250 / 270 * D
</code></pre>
where D is the degrees. 
Considering...
Violet has a 380–450 nm wavelength, &amp;
Blue has a 450–495 nm wavelength, &amp;
Green has a 495–570 nm wavelength, &amp;
Yellow has a 570–590 nm wavelength, &amp;
Orange has a 590–620 nm wavelength, &amp;
Red has a 620–750 nm wavelength,
then you just need to check if it is in those ranges, then you can classify it.
Hope this helps!

I have a project that would classify the color of a pixel. Whether it is red,violet, orange or simply any color in the color wheel. I know that there are over 16 million color combination for pixels. But I was able to read a web page that says its possible for me to do my project using the wavelengths of color. Please give me the formula to compute for the wavelength using RGB values. Thanks!

How to get the wavelength of a pixel using RGB?

V模型

我有一个项目，可以对像素的颜色进行分类。无论是红色、紫色、橙色还是色轮中的任何颜色。我知道像素有1600多万种颜色组合。但我读到了一个网页，上面说我可以用颜色的波长来做我的项目。请给我使用RGB值计算波长的公式。谢谢!

问如何使用RGB获得像素的波长？
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