rsz

Resize images as files or Buffers

rsz

Resize image files or Buffers

Depends on node-canvas which has special build instructions as it requires Cairo to be installed on your system.

rsz shares the same API as crp, except crp is for cropping images rather than resizing. See also: sz for simply obtaining the size of an image, and thmb for making thumbnails of images.

There is one method but multiple ways to use it:

rsz(src, width, height, function (err, buf) { /* */ })

Where src is a String specifying the path to the image or a Buffer containing the image data, and buf is a Buffer containing the resized image data.

rsz(src, dst, width, height, function (err) { /* */ })

Where src is a String specifying the path to the image or a Buffer containing the image data, and dst is a String specifying the path to write the output file to.

rsz(src, { width: w, height: h }, function (err, buf) { /* */ })

Where w and h are the width and height respectively, src is a String specifying the path to the image or a Buffer containing the image data, and buf is a Buffer containing the resized image data.

rsz(src, dst, { width: w, height: h }, function (err) { /* */ })

Where w and h are the width and height respectively, src is a String specifying the path to the image or a Buffer containing the image data, and dst is a String specifying the path to write the output file to.

By default, rsz will return a PNG Buffer or write a PNG file. You can change this when you pass an options object: { height: 100, width: 100, type: 'jpeg' }. You can also adjust the quality with a 'quality' property.

  • 'height' (Number, required) the height of the resized image
  • 'width' (Number, required) the width of the resized image
  • 'type' (String, optional, default: 'png') set to 'jpeg' to return a JPEG Buffer or write a JPEG file.
  • 'quality' (Number, optional) used when creating a JPEG, a number between 1 (lowest quality) and 100 (highest quality).
  • 'aspectRatio' (Boolean, optional, default: false) set to true to ensure resized image has the same aspect ratio as the original image.
var rsz = require('rsz')
  , fs  = require('fs')
 
// output resized image as a buffer 
 
rsz('/path/to/nyancat.gif', 200, 350, function (errbuf) {
  fs.writeFileSync('/path/to/nyancat_200_350.png', buf)
})
 
// supply destination file directly 
 
rsz('/path/to/nyancat.gif', 200, 350, '/path/to/nyancat_200_350.png', function (err) {
})
 
// configure the width and height with an options object 
 
rsz('/path/to/nyancat.gif', { width: 200, height: 350 }, function (errbuf) {
  fs.writeFileSync('/path/to/nyancat_200_350.png', buf)
})
 
// combine options object and output destination 
 
rsz('/path/to/nyancat.gif', { width: 200, height: 350 }, '/path/to/nyancat_200_350.png', function (err) {
})
 
// maintain aspect ratio 
 
rsz('/path/to/nyancat.gif', { width: 200, height: 200, aspectRatio: true }, function (errbuf) {
})
 
// resize only one dimension 
 
rsz('/path/to/nyancat.gif', { width: 200 }, function (errbuf) {
 
})
 
// resize only one dimension by setting the other dimension to 0 
 
rsz('/path/to/nyancat.gif', 200, 0, function (errbuf) {
 
})
 
// rsz also supports convertion between gif, png & jpeg 
 
rsz(
    '/path/to/avatar.png'
  , { width: 50, height: 50, type: 'jpeg', quality: 40 }
  , '/path/to/avatar_50_50.jpg'
  , function (err) {
      /* ... */
    }
)

rsz is Copyright (c) 2013 Rod Vagg @rvagg and licensed under the MIT licence. All rights not explicitly granted in the MIT license are reserved. See the included LICENSE file for more details.