node-opencv/examples/take-face-pics.js

var cv = require('../lib/opencv');
try {
  var vid = new cv.VideoCapture(0);

  vid.read(function(err, im){
    if (err) throw err;
    if (im.size()[0] > 0 && im.size()[1] > 0){

      im.detectObject(cv.FACE_CASCADE, {}, function(err, faces){
        if (err) throw err;
        if (!faces.length) return console.log("No Faces");

        var face = faces[0];
        var ims = im.size();
        var im2 = im.roi(face.x, face.y, face.width, face.height)
        /*
        im.adjustROI(
             -face.y
           , (face.y + face.height) - ims[0]
           , -face.x
           , (face.x + face.width) - ims[1])
           */
        im2.save('./examples/tmp/take-face-pics.jpg')
        console.log('Image saved to ./tmp/take-face-pics.jpg');
      })
    } else {
      console.log("Camera didn't return image")
    }
  });
} catch (e){
  console.log("Couldn't start camera", e)
}