colors - 色彩理论 : How to convert Munsell HVC to RGB/HSB/HSL

Question

我正在查看描述 dentry 中用于描述 dentry 颜色的标准颜色的文档。他们引用了色调、值、色度值，并指出它们来自 1905 年孟塞尔对颜色的描述:

The system of colour notation developed by A. H. Munsell in 1905 identifies colour in terms of three attributes: HUE, VALUE (Brightness) and CHROMA (saturation) [15]

HUE (H): Munsell defined hue as the quality by which we distinguish one colour from another. He selected five principle colours: red, yellow, green, blue, and purple; and five intermediate colours: yellow-red, green-yellow, blue-green, purple-blue, and red-purple. These were placed around a colour circle at equal points and the colours in between these points are a mixture of the two, in favour of the nearer point/colour (see Fig 1.).

VALUE (V): This notation indicates the lightness or darkness of a colour in relation to a neutral grey scale, which extends from absolute black (value symbol 0) to absolute white (value symbol 10). This is essentially how ‘bright’ the colour is.

CHROMA (C): This indicates the degree of divergence of a given hue from a neutral grey of the same value. The scale of chroma extends from 0 for a neutral grey to 10, 12, 14 or farther, depending upon the strength (saturation) of the sample to be evaluated.

There are various systems for categorising colour, the Vita system is most commonly used in Dentistry. This uses the letters A, B, C and D to notate the hue (colour) of the tooth. The chroma and value are both indicated by a value from 1 to 4. A1 being lighter than A4, but A4 being more saturated than A1. If placed in order of value, i.e. brightness, the order from brightest to darkest would be:

A1, B1, B2, A2, A3, D2, C1, B3, D3, D4, A3.5, B4, C2, A4, C3, C4

The exact values of Hue, Value and Chroma for each of the shades is shown below (16)

所以我的问题是，谁能将 Munsell HVC 转换为 RGB、HSB 或 HSL？

Hue    Value (Brightness) Chroma(Saturation)
===    ================== ==================
4.5    7.80               1.7
2.4    7.45               2.6
1.3    7.40               2.9
1.6    7.05               3.2
1.6    6.70               3.1
5.1    7.75               1.6
4.3    7.50               2.2
2.3    7.25               3.2
2.4    7.00               3.2
4.3    7.30               1.6
2.8    6.90               2.3
2.6    6.70               2.3
1.6    6.30               2.9
3.0    7.35               1.8
1.8    7.10               2.3
3.7    7.05               2.4

他们说 Value(Brightness) 从 0..10 变化，这很好。所以我取 7.05 表示 70.5%。

但是什么是 Hue测量在？我习惯了 色调被测量在 degrees (0..360)。但是我看到的值都是红色的 - 当它们应该更黄或棕色时。

最后，它说 Choma/Saturation 的范围可以是 0..10 ...甚至更高 - 这使它听起来像一个任意的比例。

那么任何人都可以将 Munsell HVC 转换为 HSB 或 HSL，或者更好的是，RGB？

Answer 1

您在此处给出的色调规范不完整(4.5 应该是 4.5Y 等)。由于链接已失效，如果有人感兴趣，这里的规范仍然存在:
http://web.archive.org/web/20071103065312/http://lib.umich.edu/dentlib/Dental_tables/Colorshadguid.html

我能找到的唯一免费的 Munsell 转换实用程序是:

http://web.archive.org/web/20020809130910/standards.gretagmacbeth.com/cmc/munsell.exe

正如您所看到的那样非常古老，但似乎运行良好。当前可以执行此操作的程序不是免费的:

http://livingstonmanor.net/Munsell2/index.htm

http://www.babelcolor.com/main_level/download.htm (这个有 14 天免费试用期)

孟塞尔产品的当前持有人是 X-Rite ，他们可能也有一些转换解决方案。

此外，请注意您提供的链接包含其他颜色坐标中相同颜色的定义 - 即 Yxy 和 CIE lab*。两者都可以在 http://www.colorpro.com/info/tools/convert.htm 在线免费转换或离线使用此 free color converter