sharp

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.

README

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 due to its use of libvips.

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 macOS, Windows and Linux systems running Node.js v10+ do not require any additional install or runtime dependencies.

Examples

npm install sharp

const sharp = require('sharp');

Callback

sharp(inputBuffer)
  .resize(320, 240)
  .toFile('output.webp', (err, info) => { ... });

Promise

sharp('input.jpg')
  .rotate()
  .resize(200)
  .toBuffer()
  .then( data => { ... })
  .catch( err => { ... });

Async/await

const semiTransparentRedPng = await sharp({
  create: {
    width: 48,
    height: 48,
    channels: 4,
    background: { r: 255, g: 0, b: 0, alpha: 0.5 }
  }
})
  .png()
  .toBuffer();

Stream

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)
    .composite([{
      input: roundedCorners,
      blend: 'dest-in'
    }])
    .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.

Licensing

Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 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 https://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.