Manipulate http://make8bitart.com/ using phantomjs (and a few canvas workarounds) to let the computer be the artist this example generates: http://i.minus.com/jccK6EuB7LRdl.png

generate.js

var url = 'https://lh6.googleusercontent.com/-NQAMokukfdE/AAAAAAAAAAI/AAAAAAAAAAA/zSaLZajdgEI/s48-c-k-no/photo.jpg';
var xoffset = 240;
var yoffset = 210;
var pixelSize = 7;
var viewportWidth = 800;
var viewportHeight = 670;

//
// And away we go
//

var webpage = require('webpage');
var page = webpage.create();
page.viewportSize = { width: viewportWidth, height: viewportHeight };
page.settings.webSecurityEnabled = false;
page.open('http://make8bitart.com/', function (status) {

  // set the size of the picker
  var setSize = function (size) {
    page.evaluate(function (s) {
      $('#pixel-size').val(s).trigger('change');
    }, size);
  };

  // set the color of the picker
  var setColor = function (color) {
    page.evaluate(function (c) {
      $('#hex-color').val(c).focus();
    }, color);
  };

  // How to draw a certain color at a certain location
  var drawPixel = function (color, x, y) {
    setColor(color);
    page.sendEvent('click', x, y);
  };

  // Get pixels of an image using a browser canvas render
  var getPixels = function (url, callback) {

    page.onCallback = function (width, height, data) {
      callback(width, height, data);
    };

    page.evaluate(function (url) {
      var img = new Image;
      img.onload = function () {
        var canvas = document.createElement('canvas');
        canvas.width = img.width;
        canvas.height = img.height;
        var context = canvas.getContext('2d')
        context.drawImage(img, 0, 0, img.width, img.height);
        var data = context.getImageData(0, 0, img.width, img.height).data;
        window.callPhantom(img.width, img.height, data);
      };
      img.src = url;
    }, url);

  };

  // convert a point to hex to avoid validation issues
  var toHex = function toHex(n) {
    return '0123456789ABCDEF'.charAt((n - n % 16) / 16) + '0123456789ABCDEF'.charAt(n % 16);
  }
  var convertPointToHex = function (data, o) { // ignore semi-transparency
    return toHex(data[o]) + toHex(data[o + 1]) + toHex(data[o + 2]);
  };

  // draw what we're told to
  getPixels(url, function (width, height, data) {

    setSize(pixelSize);

    var p, color;
    for (var y = 0; y < height; y++) {
      for (var x = 0; x < width; x++) {

        if (data[p + 3] === 0) { continue; } // ignore full transparency

        p = ((y * width) + x) * 4;
        color = convertPointToHex(data, p);
        drawPixel(color, xoffset + x * pixelSize, yoffset + y * pixelSize);

      }
    }

    // And then take a screenshot
    page.render('out.png');
    phantom.exit();

  });

});