▼ |  | Framework: Racket GUI Application Framework

1 | Framework Libraries Overview
2 | Application
3 | Autosave
4 | Canvas
5 | Color Model
6 | Color Prefs
7 | Color
8 | Comment Box
9 | Decorated Editor Snip
10 | Editor Snip
11 | Editor
12 | Exit
13 | Finder
14 | Frame
15 | Group
16 | GUI Utilities
17 | Handler
18 | Icon
19 | Keymap
20 | Menu
21 | Mode
22 | Number Snip
23 | Panel
24 | Pasteboard
25 | Path Utils
26 | Preferences
27 | Preferences, Textual
28 | Racket
29 | Text
30 | Splash
31 | Test
32 | Version
33 | Backwards Compatibility
34 | Signatures
35 | Unit
| Index

On this page:

color-model: rgb->xyz
color-model: rgb-color-distance
color-model: xyz->rgb
color-model: xyz?
color-model: xyz-x
color-model: xyz-y
color-model: xyz-z

top ← prev up next →

### 5`` Color Model

> > procedure

> > (color-model:rgb->xyz r g b) → color-model:xyz?

> r : number?
> g : number?
> b : number?

Converts a color represented as a red-green-blue tuple (each value from 0 to 255) into an XYZ tuple. This describes a point in the CIE XYZ color space.

> > procedure

> > (color-model:rgb-color-distance |  | red-a |  |  |  |
> > |  | green-a |  |  |  |
> > |  | blue-a |  |  |  |
> > |  | red-b |  |  |  |
> > |  | green-b |  |  |  |
> > |  | blue-b) |  | → |  | number?

> red-a : number?
> green-a : number?
> blue-a : number?
> red-b : number?
> green-b : number?
> blue-b : number?

This calculates a distance between two colors. The smaller the distance, the closer the colors should appear to the human eye. A distance of 10 is reasonably close that it could be called the same color.

This function is not symmetric in red, green, and blue, so it is important to pass red, green, and blue components of the colors in the proper order. The first three arguments are red, green and blue for the first color, respectively, and the second three arguments are red green and blue for the second color, respectively.

> > procedure

> > (color-model:xyz->rgb x y z) → (list/c number? number? number?)

> x : number?
> y : number?
> z : number?

Converts an XYZ-tuple (in the CIE XYZ colorspace) into a list of values representing an RGB-tuple.

> > procedure

> > (color-model:xyz? val) → boolean?

> val : any/c

Determines if val an xyz color record.

> > procedure

> > (color-model:xyz-x xyz) → number?

> xyz : color-model:xyz?

Extracts the x component of xyz.

> > procedure

> > (color-model:xyz-y xyz) → number?

> xyz : color-model:xyz?

Extracts the y component of xyz.

> > procedure

> > (color-model:xyz-z xyz) → number?

> xyz : color-model:xyz?

Extracts the z component of xyz.
top ← prev up next →