let butterfly; 

​

function preload(){

  butterfly = loadImage("data/butterfly.jpg");

}

​

function setup(){

  createCanvas(butterfly.width * 2, butterfly.height * 2);

}

​

function draw(){

  let tmpAry = [];

  image(butterfly, 0, 0, width, height);

  loadPixels();

​

  for (let i = 0; i < pixels.length; i+= 4){

    tmpAry.push([pixels[i], pixels[i + 1], pixels[i + 2], pixels[i + 3]]);

  }

  tmpAry.sort((a, b) => {

    return (a[0]) - (b[0]);

  });

  for (let i = 0; i < pixels.length; i+= 4){

    for (let j = 0; j < 4; j++){

        pixels[i + j] = tmpAry[i / 4][j];

    }  

  }

​

  updatePixels();

  noLoop();

}