GraphicsMagick and ImageMagick for node
When reporting bugs please include the version of graphicsmagick/imagemagick you're using (gm -version/convert -version) as well as the version of this module and copies of any images you're having problems with.
First download and install GraphicsMagick or ImageMagick. In Mac OS X, you can simply use Homebrew and do:
brew install imagemagick
brew install graphicsmagick
If you want WebP support with ImageMagick, you must add the WebP option:
brew install imagemagick --with-webp
then either use npm:
npm install gm
or clone the repo:
git clone git://github.com/aheckmann/gm.git
Subclass gm to enable ImageMagick
var fs = require('fs')
, gm = require(<
8000
/span>'gm').subClass({imageMagick: true});
// resize and remove EXIF profile data
gm('/path/to/my/img.jpg')
.resize(240, 240)
...var fs = require('fs')
, gm = require('gm');
// resize and remove EXIF profile data
gm('/path/to/my/img.jpg')
.resize(240, 240)
.noProfile()
.write('/path/to/resize.png', function (err) {
if (!err) console.log('done');
});
// some files would not be resized appropriately
// http://stackoverflow.com/questions/5870466/imagemagick-incorrect-dimensions
// you have two options:
// use the '!' flag to ignore aspect ratio
gm('/path/to/my/img.jpg')
.resize(240, 240, '!')
.write('/path/to/resize.png', function (err) {
if (!err) console.log('done');
});
// use the .resizeExact with only width and/or height arguments
gm('/path/to/my/img.jpg')
.resizeExact(240, 240)
.write('/path/to/resize.png', function (err) {
if (!err) console.log('done');
});
// obtain the size of an image
gm('/path/to/my/img.jpg')
.size(function (err, size) {
if (!err)
console.log(size.width > size.height ? 'wider' : 'taller than you');
});
// output all available image properties
gm('/path/to/img.png')
.identify(function (err, data) {
if (!err) console.log(data)
});
// pull out the first frame of an animated gif and save as png
gm('/path/to/animated.gif[0]')
.write('/path/to/firstframe.png', function (err) {
if (err) console.log('aaw, shucks');
});
// auto-orient an image
gm('/path/to/img.jpg')
.autoOrient()
.write('/path/to/oriented.jpg', function (err) {
if (err) ...
})
// crazytown
gm('/path/to/my/img.jpg')
.flip()
.magnify()
.rotate('green', 45)
.blur(7, 3)
.crop(300, 300, 150, 130)
.edge(3)
.write('/path/to/crazy.jpg', function (err) {
if (!err) console.log('crazytown has arrived');
})
// annotate an image
gm('/path/to/my/img.jpg')
.stroke("#ffffff")
.drawCircle(10, 10, 20, 10)
.font("Helvetica.ttf", 12)
.drawText(30, 20, "GMagick!")
.write("/path/to/drawing.png", function (err) {
if (!err) console.log('done');
});
// creating an image
gm(200, 400, "#ddff99f3")
.drawText(10, 50, "from scratch")
.write("/path/to/brandNewImg.jpg", function (err) {
// ...
});// passing a stream
var readStream = fs.createReadStream('/path/to/my/img.jpg');
gm(readStream, 'img.jpg')
.write('/path/to/reformat.png', function (err) {
if (!err) console.log('done');
});
// passing a downloadable image by url
var request = require('request');
var url = "www.abc.com/pic.jpg"
gm(request(url))
.write('/path/to/reformat.png', function (err) {
if (!err) console.log('done');
});
// can also stream output to a ReadableStream
// (can be piped to a local file or remote server)
gm('/path/to/my/img.jpg')
.resize('200', '200')
.stream(function (err, stdout, stderr) {
var writeStream = fs.createWriteStream('/path/to/my/resized.jpg');
stdout.pipe(writeStream);
});
// without a callback, .stream() returns a stream
// this is just a convenience wrapper for above.
var writeStream = fs.createWriteStream('/path/to/my/resized.jpg');
gm('/path/to/my/img.jpg')
.resize('200', '200')
.stream()
.pipe(writeStream);
// pass a format or filename to stream() and
// gm will provide image data in that format
gm('/path/to/my/img.jpg')
.stream('png', function (err, stdout, stderr) {
var writeStream = fs.createWriteStream('/path/to/my/reformatted.png');
stdout.pipe(writeStream);
});
// or without the callback
var writeStream = fs.createWriteStream('/path/to/my/reformatted.png');
gm('/path/to/my/img.jpg')
.stream('png')
.pipe(writeStream);
// combine the two for true streaming image processing
var readStream = fs.createReadStream('/path/to/my/img.jpg');
gm(readStream)
.resize('200', '200')
.stream(function (err, stdout, stderr) {
var writeStream = fs.createWriteStream('/path/to/my/resized.jpg');
stdout.pipe(writeStream);
});
// GOTCHA:
// when working with input streams and any 'identify'
// operation (size, format, etc), you must pass "{bufferStream: true}" if
// you also need to convert (write() or stream()) the image afterwards
// NOTE: this buffers the readStream in memory!
var readStream = fs.createReadStream('/path/to/my/img.jpg');
gm(readStream)
.size({bufferStream: true}, function(err, size) {
this.resize(size.width / 2, size.height / 2)
this.write('/path/to/resized.jpg', function (err) {
if (!err) console.log('done');
});
});