Colorimetry

【Colorimetry】

1、Example of Spectral Power Distribution Application

　　An example of the spectral power distribution of light from common objects shows that such colors arise from a range of wavelengths. Even the vivid red of a tomato involves a range of wavelengths in the red region of the visible spectrum.

　　一个普通物体上的光的SPD的示例，它表明这些颜色由一段范围的不同 wavelength 的光组成。即使西红柿耀眼的红光，也由一段范围的红色区域的 wavelength 的光组成。

　　

参考：http://hyperphysics.phy-astr.gsu.edu/hbase/vision/spd.html#c3

2、RGB Color Matching Functions

　　These are the historical color matching functions worked out by painstaking experiments. They can be used to reliably predict color perception, but most applications now use the CIE functions.

　　RGB 是过去的 matching function。现在多数应用使用 CIE function。

　　The CIE functions are derived from these RGB functions in such a way as to give all positive values. The RGB primariesmust include some subtraction to cover the entire range of color perception.

　　CIE function 的 XYZ 只用正数就可以表达所有的颜色，而RGB需要引入负值也能表达所有的颜色。

　　

参考：http://hyperphysics.phy-astr.gsu.edu/hbase/vision/colspa.html#c4

3、CIE Color Matching Function.

　　If the spectral power distribution (SPD) for a colored object is weighted by these curves, the CIE chromaticity coordinatescan be calculated.

　　

参考：http://hyperphysics.phy-astr.gsu.edu/hbase/vision/cieprim.html#c2

4、Additive Color Mixing，可叠加的颜色混合。

　　The commonly used additive primary colors are red, green and blue, and if you overlap all three in effectively equal mixture, you get white light as shown at the center.

　　

参考：http://hyperphysics.phy-astr.gsu.edu/hbase/vision/addcol.html#c1

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