threshold method

Image threshold(
  1. num threshold
)

Implementation

im.Image threshold(num threshold) {
  final im.Image result = im.Image( width: width, height: height);

  var black = new im.ColorFloat16.rgb(0, 0, 0);
  var white = new im.ColorFloat16.rgb(255,255,255);

  for (int y = 0; y < height; y++) {
    for (int x = 0; x < width; x++) {
      im.Pixel pixel = getPixel(x, y);
      var lum =  pixel.luminance ;

      if (lum < threshold) {
        result.setPixel(x, y, black);
      } else {
        result.setPixel(x, y, white);
      }
    }
  }

  return result;
}