function preload() {
  img = loadImage('data/pic.png');
  icons = {};
  for (var name in emojis) {
    icons[name] = loadImage(emojisPath + '36x36/' + name + '.png');
  }
}
Pixel mapping, each pixel of an image is translated into an emoji icon.
The pixel RGB value is mapped with the nearest (average) RGB value of an emoji.
Mapping via a [k-dimensional tree data structure](https://github.com/ubilabs/kd-tree-javascript).
See also "P_emoji_icon_analyser" for how to calculate the average color of emoji.

KEYS
s                   : save png