What is sharp?
The sharp npm package is a high-performance Node.js module for resizing, converting, and manipulating images. It is built around the libvips image processing library, which allows it to handle large images and perform operations quickly and with a low memory footprint.
What are sharp's main functionalities?
Image Resizing
Resizes an image to the specified width and height.
sharp('input.jpg').resize(300, 200).toFile('output.jpg', (err, info) => {});
Format Conversion
Converts an image from one format to another, such as JPEG to PNG.
sharp('input.jpg').toFormat('png').toBuffer().then(data => {});
Image Rotation
Rotates an image by a specified degree.
sharp('input.jpg').rotate(90).toBuffer().then(data => {});
Extracting Image Regions
Extracts a region of the image starting at the left and top offsets and with the specified width and height.
sharp('input.jpg').extract({ left: 100, top: 100, width: 300, height: 200 }).toFile('output.jpg', (err, info) => {});
Image Overlay
Overlays an image on top of another using composition.
sharp('input.jpg').composite([{ input: 'overlay.png', gravity: 'southeast' }]).toFile('output.jpg', (err, info) => {});
Adjusting Image Quality
Adjusts the quality of an image, useful for optimizing the file size.
sharp('input.jpg').jpeg({ quality: 80 }).toBuffer().then(data => {});
Other packages similar to sharp
imagemagick
ImageMagick is a software suite to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats. It is more comprehensive than sharp but can be slower and more memory-intensive.
jimp
An image processing library for Node written entirely in JavaScript, with zero native dependencies. Jimp is more accessible due to its pure JavaScript nature but generally performs slower than sharp.
gm
GraphicsMagick for node.js, which is an image processing library that is a fork of ImageMagick. It is similar to ImageMagick in functionality and also provides a comprehensive set of image manipulation features but may not be as fast as sharp.
sharp
npm install sharp
yarn add sharp
The typical use case for this high speed Node.js module
is to convert large images in common formats to
smaller, web-friendly JPEG, PNG and WebP images of varying dimensions.
Resizing an image is typically 4x-5x faster than using the
quickest ImageMagick and GraphicsMagick settings.
Colour spaces, embedded ICC profiles and alpha transparency channels are all handled correctly.
Lanczos resampling ensures quality is not sacrificed for speed.
As well as image resizing, operations such as
rotation, extraction, compositing and gamma correction are available.
Most modern 64-bit OS X, Windows and Linux (glibc) systems running
Node versions 4, 6, 8 and 10
do not require any additional install or runtime dependencies.
Examples
const sharp = require('sharp');
sharp(inputBuffer)
.resize(320, 240)
.toFile('output.webp', (err, info) => ... );
sharp('input.jpg')
.rotate()
.resize(200)
.toBuffer()
.then( data => ... )
.catch( err => ... );
const roundedCorners = Buffer.from(
'<svg><rect x="0" y="0" width="200" height="200" rx="50" ry="50"/></svg>'
);
const roundedCornerResizer =
sharp()
.resize(200, 200)
.overlayWith(roundedCorners, { cutout: true })
.png();
readableStream
.pipe(roundedCornerResizer)
.pipe(writableStream);
Documentation
Visit sharp.pixelplumbing.com for complete
installation instructions,
API documentation,
benchmark tests and
changelog.
Contributing
A guide for contributors
covers reporting bugs, requesting features and submitting code changes.
Licence
Copyright 2013, 2014, 2015, 2016, 2017, 2018 Lovell Fuller and contributors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.