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

Current Supported Prebuild binary version: Node 6 | 8 | 10 | 11
For Electron user: only binary supported version is v4. More Info On: Build For Electron

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

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).

Electron

due to something between v3 and v4, although they have the same abi but it seams not gonna work for one prebuild binary, so I only created a v4 version,you can still compile it by you self

Get All tool need, like cmake and build tool based on you OS;
before you install the package, and following code to you package.json

  "cmake-js": {
    "runtime": "electron", // it can also be node/nw
    "runtimeVersion": "3.0.0", // the version that you want like v3.0.0
    "arch": "x64" // arch
  }

then install the package by

npm i cquant // yarn should be fine

For non-electron v3 user, usually you are fine to continue coding now. 4. For electron v3 user, you may try to use in your code, if it causes error, let'go on.
(Why? Because the electron v3 and v4 have the same abi number, but due to some build tool changes in electron team, the prebuild binary wasn't compatible.) 5. You need to go to the node_modules/cquant, run command line, it will rebuild the code with the info your set in your root package.json. This should work

npm run rebuild

Async!

This package is real async, and also very fast

TODO

add para for subsampling

xVan Turing 2019

cquant