let button;

​

function setup() {

  createCanvas(400, 500);

  background(0);

  video = createCapture(VIDEO);

  video.size(400, 500);

  // video.hide();

  button = createButton("take photo");

  button.mousePressed(takePhoto);

}

​

function takePhoto() {

  video.hide();

  for (let col = 0; col < video.width; col += 10) {

    for (let row = 0; row < video.height; row += 10) {

      let c = video.get(col, row);

      stroke(color(c));

      strokeWeight(1);

      fill(c);

      ellipse(col, row, random(0, 8));

    }

  }

}

​