var scaler = 5;

var r,g,b,bright, pr,pg,pb,pbright;

​

function setup() {

  createCanvas(640, 480);

  video = createCapture(VIDEO);

  // video.hide();

  video.size(width / scaler, height / scaler);

  // frameRate(10);

}

​

function draw() {

  background(220);

  video.loadPixels();

  for (let y = 0; y < video.height; y++) {

    for (let x = 0; x < video.width; x++) {

      var index = (x + y * video.width) * 4

      r = video.pixels[index + 0];

      g = video.pixels[index + 1];

      b = video.pixels[index + 2];

      bright = (r+g+b)/3;

      if(abs(pbright,bright)<100){

        fill(bright);

      }else{

        fill(255,0,0);

      }

      // fill(bright);

      noStroke();

      rect(x*scaler,y*scaler,scaler,scaler);

      // pr = r;

      // pg = g;

      // pb = b;

      pbright=bright;

    }

  }

}