Node.js: image resizing without ImageMagick

I would vote for sharp:

sharp('input.jpg')
  .resize(200, 200)
  .toFile('ouput.jpg', function(err) {
    // output.jpg is a 200 pixels wide and 200 pixels high image
    // containing a scaled and cropped version of input.jpg
  });

It's fast, typically 6x faster than the fastest imagemagick-based node bindings, and runs in very little memory, perhaps 10x less. sharp links to the libvips image library directly, there is no shelling out to an external program, and the library itself is faster and more efficient than *magick at this task. It supports useful things like stream, buffer and filesystem input and output, colour management, transparency, promises, overlays, WebP, SVG, and more.

As of sharp 0.20, npm will automatically download complete pre-compiled binaries on most platforms, so there's no need for node-gyp. Just enter:

npm install sharp

or:

yarn add sharp

And off you go.

I have recently started developing an image processing module for NodeJS without any runtime dependencies (read why). It's still at early stages, but already usable.

What you are asking for would be done as follows:

image.resize(200, 200, function(err, image){
    // encode resized image to jpeg and get a Buffer object
    image.toBuffer('jpg', function(err, buffer){
        // save buffer to disk / send over network / etc.
    });
});

More info at the module's Github repo.

Take a look at lwip : https://github.com/EyalAr/lwip

Very simple and easy to use

npm install lwip

and then in your node code,

// obtain an image object:
require('lwip').open('image.jpg', function(err, image){

  // check err...
  // define a batch of manipulations and save to disk as JPEG:
  image.batch()
    .scale(0.75)          // scale to 75%
    .rotate(45, 'white')  // rotate 45degs clockwise (white fill)
    .crop(200)            // crop a 200X200 square from center
    .blur(5)              // Gaussian blur with SD=5
    .writeFile('output.jpg', function(err){
      // check err...
      // done.
    });

});

I have successfully implemented this in my file uploader and it works like a charm.

There is a good image manipulation library written entirely in JavaScript, without dependencies to any other libraries, Jimp. https://github.com/oliver-moran/jimp

Example usage:

var Jimp = require("jimp");

// open a file called "lenna.png"
Jimp.read("lenna.png", function (err, lenna) {
    if (err) throw err;
    lenna.resize(256, 256)            // resize
         .quality(60)                 // set JPEG quality
         .write("lena-small.jpg"); // save
});