packages/plugin-dither/src/index.js
function dither(cb) {
  const rgb565Matrix = [1, 9, 3, 11, 13, 5, 15, 7, 4, 12, 2, 10, 16, 8, 14, 6];
  this.scanQuiet(0, 0, this.bitmap.width, this.bitmap.height, function(
    x,
    y,
    idx
  ) {
    const thresholdId = ((y & 3) << 2) + (x % 4);
    const dither = rgb565Matrix[thresholdId];
    this.bitmap.data[idx] = Math.min(this.bitmap.data[idx] + dither, 0xff);
    this.bitmap.data[idx + 1] = Math.min(
      this.bitmap.data[idx + 1] + dither,
      0xff
    );
    this.bitmap.data[idx + 2] = Math.min(
      this.bitmap.data[idx + 2] + dither,
      0xff
    );
  });

  if (isNodePattern(cb)) {
    cb.call(this, null, this);
  }

  return this;
}
function dither(cb) {
  const rgb565Matrix = [1, 9, 3, 11, 13, 5, 15, 7, 4, 12, 2, 10, 16, 8, 14, 6];
  this.scanQuiet(0, 0, this.bitmap.width, this.bitmap.height, function(
    x,
    y,
    idx
  ) {
    const thresholdId = ((y & 3) << 2) + (x % 4);
    const dither = rgb565Matrix[thresholdId];
    this.bitmap.data[idx] = Math.min(this.bitmap.data[idx] + dither, 0xff);
    this.bitmap.data[idx + 1] = Math.min(
      this.bitmap.data[idx + 1] + dither,
      0xff
    );
    this.bitmap.data[idx + 2] = Math.min(
      this.bitmap.data[idx + 2] + dither,
      0xff
    );
  });

  if (isNodePattern(cb)) {
    cb.call(this, null, this);
  }

  return this;
}
function dither ( cb ) { const rgb565Matrix = [ 1 , 9 , 3 , 11 , 13 , 5 , 15 , 7 , 4 , 12 , 2 , 10 , 16 , 8 , 14 , 6 ] ; this . scanQuiet ( 0 , 0 , this . bitmap . width , this . bitmap . height , function ( x , y , idx ) { const thresholdId = ( ( y & 3 ) << 2 ) + ( x % 4 ) ; const dither = rgb565Matrix [ thresholdId ] ; this . bitmap . data [ idx ] = Math . min ( this . bitmap . data [ idx ] + dither , 0xff ) ; this . bitmap . data [ idx + 1 ] = Math . min ( this . bitmap . data [ idx + 1 ] + dither , 0xff ) ; this . bitmap . data [ idx + 2 ] = Math . min ( this . bitmap . data [ idx + 2 ] + dither , 0xff ) ; } ) ; if ( isNodePattern ( cb ) ) { cb . call ( this , null , this ) ; } return this ; }
Apply a ordered dithering effect
@param {function(Error, Jimp)} cb (optional) a callback for when complete
@returns {Jimp} this for chaining of methods
Apply a ordered dithering effect