PNG Crop

Small PNG crop utility, written in pure JS for Node.

npm install png-crop

Usage

(Check out the example folder.)

Both methods take a image path/stream/buffer as input, and a configuration with the keys width, height (mandatory, can be arbitrarily large) and top and left (optional).

Crop and output to file

var PNGCrop = require('png-crop');
 
// if you don't know the image's dimension and want to crop for a point all the
// way til bottom right, just pass a big width/height
var config1 = {width: 100, height: 62, top: 95, left: 110};
// pass a path, a buffer or a stream as the input
PNGCrop.crop('1.png', 'expectedCropTopLeftConfig.png', config1, function(err) {
  if (err) throw err;
  console.log('done!');
});

Crop and get the output stream

var PNGCrop = require('png-crop');
 
// optionally pass top and left to the configurations as the upper left corner
// from which to start cropping
var config2 = {width: 53, height: 114};
 
var imgBuffer = fs.readFileSync('1.png');
PNGCrop.cropToStream(imgBuffer, config2, function(err, outputStream) {
  if (err) throw err;
  outputStream.pipe(fs.createWriteStream('expectedCrop.png'));
});

License

MIT.