【筆記】Color Appearance Attribute

	關於色外貌屬性的筆記。

 

色外貌屬性（Color Appearance Attribute）

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色外貌屬性簡述如下：

• Brightness (Q)

An area exhibited more or less light.

• Lightness (J)

An area exhibited more or less light relative to a reference white.

\[ \style{text-align:left;} {\begin{align*} Lightness=\frac{Brightness}{Brightness_{white}} \label{01} \tag{01} \end{align*}} \]

• Colorfulness

An area exhibited more or less chromatic.

• Chroma

The colorfulness judged as a proportion of the brightness of a reference white.

\[ \style{text-align:left;} {\begin{align*} Chroma=\frac{Colorfulness}{Brightness_{white}} \label{02} \tag{02} \end{align*}} \]

• Saturation

The colorness in proportion to its brightness.

\[ \style{text-align:left;} {\begin{align*} Saturation=\frac{Colorfulness}{Brightness}=\frac{Chroma}{Lightness} \label{03} \tag{03} \end{align*}} \]

• Hue

An area appears to be similar to one of the 4 unitary hues: red, yellow, green, and blue, or a co,bination of two of them.

• Hue Composition (H)

Color Appearance. (Y50R)

• Hue Angle (h)

Color Difference. (0° to 360°)