function loadPNG(path) {
  return new Promise(function (resolve, reject) {
    di.fs.readFile(path, function (error, imageData) {
      if (error) {
        return reject(error);
      }

      new di.PNG().parse(imageData, function (error, data) {
        if (error) {
          return reject(error);
        }

        resolve(data);
      });
    });
  });
}
Read and parse a PNG image file

@param  {String}  path the absolute path of the image
@return {Promise} resolve with the parsed PNG image