https://github.com/tmcw/relative-luminance

Calculate the relative luminance of an RGB triplet color.
https://github.com/tmcw/relative-luminance

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Calculate the relative luminance of an RGB triplet color.

• Host: GitHub
• URL: https://github.com/tmcw/relative-luminance
• Owner: tmcw
• Created: 2013-09-05T15:12:21.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2020-03-17T04:05:08.000Z (almost 5 years ago)
• Last Synced: 2024-10-12T04:16:49.008Z (4 months ago)
• Language: JavaScript
• Homepage:
• Size: 29.3 KB
• Stars: 28
• Watchers: 3
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md

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README

        
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## relative-luminance

    npm install relative-luminance

Calculate the [relative luminance](http://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef) of

an RGB triplet color.

Note that as of 1.0.0, this module doesn't directly export a function if you're using

CommonJS: use the `default` export, like:

```js

var luminance = require('relative-luminance').default;

```

### API

##### Table of Contents

-   [relativeLuminance](#relativeluminance)

    -   [Parameters](#parameters)

    -   [Examples](#examples)

#### relativeLuminance

Given a 3-element array of R, G, B varying from 0 to 255, return the luminance

as a number from 0 to 1.

##### Parameters

-   `rgb` **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)<[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)>** 3-element array of a color

##### Examples

```javascript

var luminance = require('relative-luminance');

var black_lum = luminance([0, 0, 0]); // 0

```

Returns **[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)** luminance, between 0 and 1