cwebp

node-webp

Node.js wrapper for cwebp binary

Installation

npm install cwebp

Requirements

WebP library should be installed and its binaries should be in $PATH.

Usage

var Webp = require('cwebp');

var webp = new Webp(source);

Available source types

When source is a string node-webp treats it as a file path.

var Webp = require('cwebp');

var webp = new Webp('image.jpeg');

It also accepts Buffers and Streams.

var webp = new Webp(buffer);

var webp = new Webp(stream);

Converting image to WebP

webp.write('image.webp', function(err) {
    console.log('converted');
});

Getting converted image as a Buffer

webp.toBuffer(function(err, buffer) {
    // ...
});

Getting converted image as a readable Stream

webp.stream(function(err, stream) {
    // ...
});

Working with Streams and Buffers

Currently WebP library have no inner support for streaming, so it only works with files.

So, when Buffer or Stream is used node-webp creates a temporary file to store its content.

To prevent leaks node-webp creates temporary files only when .write(), .stream() or .toBuffer() is called.

It removes all temporary files after conversion, but before triggering a callback.

So, converting Stream into a Buffer will cause two temporary files to be created and then removed.

It also means that node-webp will start listening for new data in the source stream only when .write(), .stream() or .toBuffer() is called.

Using promises

node-webp supports A+ promises.

webp.write('image.webp').then(function() {
    // ...
});

webp.toBuffer().then(function(buffer) {
    // ...
});

webp.stream().then(function(stream) {
    // ...
});

node-webp use when library.

Specifying conversion options

node-webp provides helper function for most of cwebp conversion options. For the full list of available helpers see methods.json file.

webp.quality(60);

Sending raw command

webp.command('-d', 'dump.pgm');