extract-colors

Extract Colors

Extract color palettes from images.
Simple use, < 6kB minified, gzip ≈ 2kB, fast process and no dependencies for browser.
Need image reader dependence for node.js

Website | Demo | Guide

Requirements

Browsers

• Firefox: 29+
• Chrome: 33+
• Edge: 12+
• Opera: 19+
• Safari: 8+
• Webview Android: 4.4.3+
• Samsung Internet: 2.0+
• Internet Explorer

Node

• Node.js: 6.0+

Install

For browser

npm install --save extract-colors

For node.js

Need to install an ImageData extractor like get-pixels

npm install --save extract-colors get-pixels

Usage

Browser example

import { extractColors } from 'extract-colors'

const src = 'my-image.jpg'

extractColors(src)
  .then(console.log)
  .catch(console.error)

You can use different types for src param (String for a path of image, HTMLImageElement or ImageData).

Node.js example

const path = require('path')
const getPixels = require("get-pixels")
const { extractColors } = require('extract-colors')

const src = path.join(__dirname, './my-image.jpg')

getPixels(src, (err, pixels) => {
  if(!err) {
    const data = [...pixels.data]
    const width = Math.round(Math.sqrt(data.length / 4))
    const height = width

    extractColors({ data, width, height })
      .then(console.log)
      .catch(console.log)
  }
})

This example use get-pixels but you can change the lib. Just send and ImageData object to extractColors(imageData).

ExtractorOptions

const options = {
  pixels: 64000,
  distance: 0.22,
  colorValidator: (red, green, blue, alpha = 255) => alpha > 250,
  saturationDistance: 0.2,
  lightnessDistance: 0.2,
  hueDistance: 0.083333333
}

extractColors(src, options)
  .then(console.log)
  .catch(console.error)

pixels
Total pixel number of the resized picture for calculation
Type: Integer
Default: 64000

distance
From 0 to 1 is the color distance to not have near colors (1 distance is between white and black)
Type: Number
Default: 0.22

colorValidator
Test function to enable only some colors
Type: Function
Default: (red, green, blue, alpha = 255) => alpha > 250

crossOrigin
Only for browser, can be 'Anonymous' to avoid client side CORS (the server side images need authorizations too)
Type: String
Default: null

saturationDistance
Minimum saturation value between two colors otherwise the colors will be merged (from 0 to 1) Type: String
Default: 0.2

lightnessDistance
Minimum lightness value between two colors otherwise the colors will be merged (from 0 to 1) Type: String
Default: 0.2

hueDistance
Minimum hue value between two colors otherwise the colors will be merged (from 0 to 1) Type: String
Default: 0.083333333

Return of the promise

Array of colors with the followed properties:

[
  {
    hex: "#858409",​​
    red: 133,​​
    green: 132,​​
    blue: 9,​​
    hue: 0.16532258064516128,​​
    intensity: 0.4862745098039216,​​
    lightness: 0.2784313725490196,​​
    saturation: 0.8732394366197184,
    area: 0.0004
  },
  ...
]

Field	Example	Type	Description
hex	#858409	String	color in hexadecimal string
red	133	Integer	red canal from 0 to 255
green	132	Integer	green canal from 0 to 255
blue	9	Integer	blue canal from 0 to 255
hue	0.1653	Number	color tone from 0 to 1
intensity	0.4862	Number	color intensity from 0 to 1
lightness	0.2784	Number	color lightness from 0 to 1
saturation	0.8732	Number	color saturation from 0 to 1
area	0.0004	Number	area of the color and his neighbouring colors from 0 to 1

License

Copyright (C) 2019 Damien Doussaud

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.