Get the width and height of an image in node.js

https://github.com/nodeca/probe-image-size

More interesting problem is "how to detect image size without full file download from remote server". probe-image-size will help. Of course, it supports local streams too.

It's written in pure JS and does not need any heavy dependencies (ImageMagick and so on).

Yes this is possible but you will need to install GraphicsMagick or ImageMagick.

I have used both and I can recommend GraphicsMagick it's lot faster.

Once you have installed both the program and it's module you would do something like this to get the width and height.

gm = require('gm');

// obtain the size of an image
gm('test.jpg')
.size(function (err, size) {
  if (!err) {
    console.log('width = ' + size.width);
    console.log('height = ' + size.height);
  }
});

Installing GraphicsMagick or ImageMagick isn't at all needed, determining the dimensions of a image is as easy as looking at the header. image-size is a pure javascript implementation of said feature which is very easy to use.

https://github.com/netroy/image-size

var sizeOf = require('image-size');
sizeOf('images/funny-cats.png', function (err, dimensions) {
  console.log(dimensions.width, dimensions.height);
});