let pastPixels = [];

let threshSlider

​

function setup() {

  createCanvas(640, 480);

  myVideo = createCapture(VIDEO);

  myVideo.size(width, height);

  myVideo.hide();

​

  threshSlider = createSlider(0, 255, 40);

}

​

​

function draw() {

  myVideo.loadPixels();

​

  const currentPixels = myVideo.pixels;

  let threshValue = threshSlider.value();

​

​

  for (let y = 0; y < height; y++) {

    for (let x = 0; x < width; x++) {

      const i = (y * width + x) * 4

​

      const rDiff = abs(currentPixels[i + 0] - pastPixels[i + 0]);

      const gDiff = abs(currentPixels[i + 1] - pastPixels[i + 1]);

      const bDiff = abs(currentPixels[i + 2] - pastPixels[i + 2]);

​

​

      // set past pixels to current pixels

      pastPixels[i + 0] = currentPixels[i + 0];

      pastPixels[i + 1] = currentPixels[i + 1];

      pastPixels[i + 2] = currentPixels[i + 2];

      pastPixels[i + 3] = currentPixels[i + 3];

​

      avgDiff = (rDiff + gDiff + bDiff) / 3;

​

      if (avgDiff < threshValue) {

        currentPixels[i + 0] = random(255);

        currentPixels[i + 1] = random(255);

        currentPixels[i + 2] = random(255);

        currentPixels[i + 3] = 30;

      } else {

        currentPixels[i + 0] = 0

        currentPixels[i + 1] = 0

        currentPixels[i + 2] = 0

        currentPixels[i + 3] = 255;

      }

    }

  }

​

  myVideo.updatePixels();

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

}