import processing.video.*;

Capture liveVideo;

void setup(){
  size(640, 480);
  noFill();
  noStroke();

  liveVideo = new Capture(this, 640, 480, 25);
}

void draw() {
  for (int i = 0; i < 100; i++) {
    drawPoint(liveVideo.pixels);
  }
}

void captureEvent(Capture liveVideo) {
  liveVideo.read();
}

void drawPoint(int[] pixelArray) {
  int x = int(random(liveVideo.width));
  int y = int(random(liveVideo.height));
  color col = pixelArray[y * liveVideo.width + x];
  fill(col, 127);
  ellipse(x, y, 6, 6);
}