pngquant

The pngquant utility as a readable/writable stream

Usage no npm install needed!

<script type="module">
  import pngquant from 'https://cdn.skypack.dev/pngquant';
</script>

README

node-pngquant

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The pngquant command line utility as a readable/writable stream.

The constructor optionally takes an array of command line options for the pngquant binary (defaults to [256]):

var PngQuant = require('pngquant'),
  myPngQuanter = new PngQuant([192, '--quality', '60-80', '--nofs', '-']);

sourceStream.pipe(myPngQuanter).pipe(destinationStream);

PngQuant as a web service (sends back a png with the number of colors quantized to 128):

var PngQuant = require('pngquant'),
  http = require('http');

http
  .createServer(function (req, res) {
    if (req.headers['content-type'] === 'image/png') {
      res.writeHead(200, { 'Content-Type': 'image/png' });
      req.pipe(new PngQuant([128])).pipe(res);
    } else {
      res.writeHead(400);
      res.end('Feed me a PNG!');
    }
  })
  .listen(1337);

Installation

Make sure you have node.js and npm installed, and that the pngquant binary is in your PATH, then run:

npm install pngquant

License

3-clause BSD license -- see the LICENSE file for details.