ℹ️ For GraphicsMagick version please see tag v0.2.1.

---

colour-extractor

Extracts colour palettes from photos using k-means clustering in LAB colour space.

Installation

Is as simple as with any other Node.js module:

$ npm install @colour-extractor/colour-extractor

Note: This module contains native Rust libraries. Please open an issue if your platform isn't supported.

Usage

colour-extractor exports two functions:

const { topColours, topColoursHex } = require('@colour-extractor/colour-extractor');
const colours = await topColours('./photos/cats/tigre.jpg');
console.log(colours);
// => [ [158, 64, 75], ... ]

topColours function needs a path to your image (see below for supported formats) and it resolves to an Array containing RGB triplet for each prominent colour:

[
  [46, 70, 118],
  [0, 0, 2],
  [12, 44, 11]
]

topColoursHex on the other hand returns hex codes (with # included):

const hexColours = await topColoursHex('./photos/cats/tigre.jpg');
console.log(hexColours);
// => ["#2e4676", "#000002", "#0c2c0b"]

Supported image formats

All major image formats are supported, including PNG, JPG and WebP. Please see image-rs's documentation for a full list. Note that file extension is used for determining the image type.

How does it work?

Here's the simplified algorithm:

1. Image is scaled down to 48x48px with a fast nearest-neighbour algorithm.
2. Colours are grouped into up to 16 clusters using k-means clustering.
3. Identified clusters are further refined using CIEDE2000 colour distance, removing any duplicates.

Licence

colour-extractor is published under MIT license.

Photos used the examples above can be found on Unsplash:

• https://unsplash.com/photos/7QaYj09Wbhs
• https://unsplash.com/photos/pPRT4CLykp8
• https://unsplash.com/photos/ttF84ygvliI