Package Exports

cquant

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (cquant) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

CQuant

Usage

npm i cquant

Basic

const cquant = require('cquant')
// work best with sharp for converting image to RAW buffer
const sharp = require('sharp')
sharp('path/to/image')
  .raw() // convert raw buffer like RGB RGB RGB RGB
  .toBuffer((err, buffer, info) => {
    if (!err) {
      // you need to set the buffer and
      // the depth(only 3 for( RGB),4 (for RGBA) are accepted )
      // you can use callback, or leave it empty for promise
      let iWantForColor = 4
      cquant.paletteAsync(buffer, info.channels, iWantForColor).then(res => {
        console.log(res)
      }).catch(err => {
        console.log(err)
      })
    }
  })

With `async.queue`

If you have lots of image to process, the best way to do it is using async.queue for parallel, and control-able

// test/example.js
const myQueue = async.queue(async (filePath) => {
  // note : i am using the `async` function, so the callback is not needed
  const img = await sharp(filePath)
    .raw() // to raw
    .toBuffer({ resolveWithObject: true })
  const palette = await cquant.paletteAsync(img.data, img.info.channels, 5)
  console.log(palette)
}, os.cpus().length - 1)

Perf

test result will be diff based on your local machine

JPG 5572 x 3715

Program	Time(ms)
cquant	14-15 ms
image-palette	N/A

N/A: crashed

JPG 1920 x 1280

Program	Time(ms)
cquant	3ms
image-palette	950ms

Async!

This package is real async, and also very fast

TODO

add para for subsampling

xVan Turing 2019

cquant