Node.js wrapper for cwebp and dwebp binaries from WebP image processing utility.
Installation
Getting latest version of WebP
You can get latest WebP source, pre-compiled binaries and installation instructions from its official website, or from its downloads repository.
Linux users may use this installation script to automatically download and install the latest WebP binaries:
curl -s https://raw.githubusercontent.com/Intervox/node-webp/latest/bin/install_webp | sudo bash
MacOS users may install WebP using homebrew:
or MacPorts:
sudo port selfupdate
sudo port install webp
If none of it suit your needs, you may build the WebP utilities yourself.
WebP versions compatibility
node-webp version |
Fully compatible WebP versions | Partially compatible WebP versions |
|---|---|---|
0.1.x |
all versions | all versions |
1.x |
0.4.1 and later |
all versions |
2.x |
0.5.0 and later |
all versions |
Usage
var CWebp = require('cwebp').CWebp; var DWebp = require('cwebp').DWebp; var encoder = new CWebp(source_image); var decoder = new DWebp(source_webp);
or
// new is optional var encoder = CWebp(source_image); var decoder = DWebp(source_webp);
or
// Backward-compatibility with cwebp@0.1.x var CWebp = require('cwebp');
Specifying path to cwebp binary
By default node-webp looks for cwebp and dwebp binary in your $PATH.
Specifying path as a constructor option
var Webp = require('cwebp'); var binPath = require('webp').cwebp; var webp = new Webp(source, binPath);
Changing default behaviour
var CWebp = require('cwebp').CWebp; CWebp.bin = require('webp').cwebp; var encoder = new CWebp(source);
var DWebp = require('cwebp').DWebp; DWebp.bin = require('webp').dwebp; var decoder = new DWebp(source);
N.B.: webp npm module provide old webp 0.3.x binaries.
Available source types
When source is a string node-webp treats it as a file path.
var CWebp = require('cwebp').CWebp; var DWebp = require('cwebp').DWebp; var encoder = new CWebp('original.jpeg'); var decoder = new DWebp('converted.webp');
It also accepts Buffers and Streams.
var encoder = new CWebp(buffer);
var decoder = new DWebp(stream);
Note that node-webp will start consuming the input stream
only when .write(), .stream() or .toBuffer() is called.
Encoding and decoding WebP images
encoder.write('image.webp', function(err) { console.log(err || 'encoded successfully'); });
decoder.write('image.png', function(err) { console.log(err || 'decoded successfully'); });
Getting output image as a Buffer
decoder.toBuffer(function(err, buffer) { // ... });
Getting output image as a readable Stream
var stream = encoder.stream(); stream.pipe(destination); stream.on('error', function(err) { // something bad happened });
Using promises
node-webp supports promises.
encoder.write('image.webp').then(function() { // ... });
encoder.toBuffer().then(function(buffer) { // ... });
decoder.stream().then(function(stream) { // ... });
Specifying conversion options
node-webp provides helper functions for most of cwebp and dwebp conversion options.
For the full list of available helpers see methods.json file.
encoder.quality(60); decoder.tiff();
Sending raw command
encoder.command('-d', 'dump.pgm');
Providing custom spawn options
encoder.spawnOptions({detached: true});
