The (Hue, Saturation, Value) model, also known as '''HSB''' (Hue, Saturation, Brightness), defines a Color Space in terms of three constituent components:
- Hue , the Color type (such as red, blue, or yellow):
- --- Ranges from 0–360 in most applications. Each value corresponds to one color. Examples: 0 is red, 45 is a shade of orange and 55 is a shade of yellow.
- Saturation , the intensity of the color:
- --- Ranges from 0–100%. 0 means no color, i.e., a shade of grey between black and white. 100 means intense color.
- --- Also sometimes called the "purity" by analogy to the Colorimetric quantities Excitation Purity and Colorimetric Purity .
- Value , the Brightness of the color:
- --- Ranges from 0–100%. 0 is always black. Depending on the saturation, 100 may be white or a more or less saturated color.
The HSV model was created in 1978 by Alvy Ray Smith . It is a Nonlinear Transformation of the RGB Color Space , and may be used in Color Progression s. Note that HSV and HSB are the same, but HSL is different.
- a---b or another CIE -based color model.
The HSV model is commonly used in computer Graphics Applications . In various application contexts, a user must choose a color to be applied to a particular graphical element. When used in this way, the HSV Color Wheel is often used. In it, the hue is represented by a circular region; a separate triangular region may be used to represent saturation and value. Typically, the vertical axis of the triangle indicates saturation, while the horizontal axis corresponds to value. In this way, a color can be chosen by first picking the hue from the circular region, then selecting the desired saturation and value from the triangular region.
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60^\circ imes rac{G - B}{\mathit{MAX} - \mathit{MIN}} + 360^\circ, & \mbox{if } \mathit{MAX} = R \ &\mbox{and } G < B \
60^\circ imes rac{B - R}{\mathit{MAX} - \mathit{MIN}} + 120^\circ, & \mbox{if } \mathit{MAX} = G \
60^\circ imes rac{R - G}{\mathit{MAX} - \mathit{MIN}} + 240^\circ, & \mbox{if } \mathit{MAX} = B
\end{cases}
In computer graphics, sometimes each HSV and RGB parameter is represented by an integer from 0 to 255 instead of a real number. In this case, the transforms do not cover all the points in the target space and some distortion is caused by rounding. For example:
- the HSV point (0, 255, 255) is mapped to the RGB point (255, 0, 0) and
- the HSV point (1, 255, 255) is mapped to the RGB point (255, 6, 0),
but no HSV points map to the 5 RGB points in between: (255, k, 0), k = 1 to 5.
See Also: Complementary color
We regard two colors as complementary if when mixed together they produce a shade of grey. Given a color (H, S, V) in HSV color space, there exists a complement (H', S', V') such that when (H, S, V) and (H', S', V') are mixed in equal proportions, the saturation of the resulting color is 0. Then,
- Raphael Gonzalez, Richard E. Woods (2002) ''Digital Image Processing,'' 2nd ed. Prentice Hall Press, ISBN 0-201-18075-8, p. 295.
- Charles Poynton. Frequently-Asked Questions about Color . 1997.
- Donald Hearn, M. Pauline Baker (1986) ''Computer Graphics.'' Prentice Hall International, ISBN 0-13-165598-1, pp. 302-205.
