ycaihua / color-hash

Generate color based on the given string (using HSL color space and BKDRHash).

Color Hash

Generate color based on the given string.

Demo

https://zenozeng.github.io/color-hash/demo/

Usage

Browser

bower install color-hash

A UMD version of ColorHash was located in dist/.

Note that Array.prototype.map was used in color-hash, a pollfill must be provided if you want to use it in IE8.

Basic

var colorHash = new ColorHash();

// in HSL, Hue ∈ [0, 360), Saturation ∈ [0, 1], Lightness ∈ [0, 1]
colorHash.hsl('Hello World'); // [ 225, 0.65, 0.35 ]

// in RGB, R, G, B ∈ [0, 255]
colorHash.rgb('Hello World'); // [ 135, 150, 197 ]

// in HEX
colorHash.hex('Hello World'); // '#8796c5'

Custom Hash Function

var customHash = function(str) {
    var hash = 0;
    for(var i = 0; i < str.length; i++) {
        hash += str.charCodeAt(i);
    }
    return hash;
};
var colorHash = new ColorHash({hash: customHash});
colorHash.hsl('Hello World!');
colorHash.rgb('Hello World!');
colorHash.hex('Hello World!');

Custom Lightness

var colorHash = new ColorHash({lightness: 0.5});

var colorHash = new ColorHash({lightness: [0.35, 0.5, 0.65]});

Custom Saturation

var colorHash = new ColorHash({saturation: 0.5});

var colorHash = new ColorHash({saturation: [0.35, 0.5, 0.65]});

Node.JS

npm install color-hash --save

var ColorHash = require('color-hash');

License

MIT.

FAQ

How does it work?

Use the hash function (default is BKDRHash) to calculate the hash of the given string,

Hue = hash % 359. (Note that 359 is a prime)
Saturation = SaturationArray[hash / 360 % SaturationArray.length]
Lightness = LightnessArray[hash / 360 / Saturation.length % LightnessArray.length]

By default,
SaturationArray = LightnessArray = [0.35, 0.5, 0.65]

Why not LAB?

Though LAB is more perceptually uniform, HSL is easier to control. Simply sets lightness and saturation and change hue uniformly can generate uniform colors.

Dev

Test

sudo npm install -g mocha
sudo npm install -g istanbul
npm test

Coverage Report

https://zenozeng.github.io/color-hash/coverage/lcov-report/lib/index.html

Build browser js

sudo npm install -g browserify
npm run build

Follow Semantic Versioning

http://semver.org/lang/zh-CN/