node-webp
Node.js wrapper for cwebp and dwebp binaries from WebP image processing utility.
Installation
npm install cwebp
WebP
Getting latest version ofYou 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 latest WebP binaries:
curl -s https://raw.githubusercontent.com/Intervox/node-webp/latest/bin/install_webp | sudo bash
MacOS users may install WebP using MacPorts:
sudo port selfupdate
sudo port install webp
If none of it suit your needs, you may build the WebP utilities yourself.
WebP
Alternative ways to installMacOS users may install webp 0.5.0
using homebrew:
brew install webp
You may also install webp 0.3.x
as npm module:
npm install webp
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 [email protected]
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 listening to the data in a source stream
only when .write()
, .stream()
or .toBuffer()
is called.
Encoding and decodind 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 A+ promises.
encoder.write('image.webp').then(function() {
// ...
});
encoder.toBuffer().then(function(buffer) {
// ...
});
decoder.stream().then(function(stream) {
// ...
});
node-webp
uses when.js library.
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');