README.md

Color-diff

Implements the CIEDE2000 color difference algorithm, conversion between RGB and LAB color and mapping all colors in palette X to the closest color in palette Y based on the CIEDE2000 difference.

Installation

npm install color-diff --save

Tests

Are located in the test/ folder and are run by:

npm test

Usage

var diff = require('color-diff');

diff.closest(color, palette, bc)

Returns the closest color. The parameter bc is optional and is used as background color when the color and/or palette uses alpha channels.

var color = { R: 255, G: 1, B: 30 };
// red, green, blue
var palette = [ {R: 255, G: 0, B: 0 },
                {R: 0, G: 255, B: 0 },
                {R: 0, G: 0, B: 255} ];

diff.closest(color, palette); // {R: 255, G: 0, B: 0 }, red

The result above is obvious, but diff.closest could deal with more complicated cases.

diff.furthest(color, palette, bc)

Returns the most different color. The parameter bc is optional and is used as background color when the color and/or palette uses alpha channels.

var color = { R: 255, G: 255, B: 255 };
// black, white
var palette = [ {R: 0, G: 0, B: 0 }, {R: 255, G: 255, B: 255 } ];

diff.furthest(color, palette); // {R: 0, G: 0, B: 0 }, black

The result above is obvious, but diff.furthest could deal with more complicated cases.

diff.map_palette(palette1, palette2)

Returns a mapping from the colors in palette1 to palette2.

color

Object

color is an object containing 3 properties: 'R', 'G', 'B', such as:

{ R: 255, G: 1, B: 0 }

There is an optional property 'A', which specifies the alpha channel between 0.0 and 1.0.

Each RGBA-color is transformed into a RGB-color before being used to calculate the CIEDE2000 difference, using the specified background color (defaults to white).

palette

Array.<Object>

Color palette array which contains many color-like objects.

Author

Markus Ekholm

License

3-clause BSD. For details see COPYING.