misund / get-relative-luminance

Get relative luminance from a color string.

Get relative luminance

get-relative-luminance calculates a CSS color's relative luminance based on this definition from W3C.

It doesn't handle transparency as of yet.

Installation

$ npm install get-relative-luminance

Usage

import getRelativeLuminance from 'get-relative-luminance'

getRelativeLuminance('rgb(255, 255, 255)') // 1
getRelativeLuminance('white') // 1
getRelativeLuminance('hsl(0, 0%, 0%)') // 0

Signature

;(
  color: string,
  {
    ignoreTransparency,
  }?: {
    ignoreTransparency?: boolean | undefined
  },
) => number

Contributing

I appreciate your issues and PRs on Github!

Testing

yarn build && yarn test

Releasing

This project uses np.

1. Make sure your changes are in master
2. Run yarn release
3. Follow the interactive release guide