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

View Latest Doc on Github

Preview

Screenshot from 2019-02-09 15-16-53.png

Usage

Current Supported Prebuild binary version: Node 6 | 8 | 10 | 11
For Electron user: Prebuild Supported Version v3 and v4.0.4

Install

npm i cquant

Electron User

After running the install command make sure to use electron-rebuild to rebuild it for electron, usually it will just download the prebuild.

Async!

This package is real async. You can run multiple task without blocking the main loop

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) and 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

Build Your Self

CMake

You need to install CMake based on your System.

Build Tool

To be able to build from the source, you also need the standard build tool based on your OS.

For Windows User

You can use this awesome app windows-build-tools to auto download all tools needed, if you don't have visual studio installed
If you have already installed a visual studio like vs2017, basicly you just need to enable c++ developement(it's gonna be huge).

Build it

for more info you can view project cmake-js Basically you need run this command

cmake-js -r electron -v 4.0.4 rebuild # for electron
cmake-js -r node -v 10.0.0 rebuild # for node

And of course if you use electron-prebuild make sure you add the cache file mentioned before

TODO

add para for subsampling

xVan Turing 2019

cquant