Pointillism
by Daniel Shiffman.

Mouse horizontal location controls size of dots.
Creates a simple pointillist effect using ellipses colored
according to pixels in an image.
*
Created 2 May 2005

 
PImage a;
void setup()
{
  a = loadImage("eames.jpg");
  size(200,200);
  noStroke();
  background(255);
  smooth();
}

void draw()
{ 
  float pointillize = 2.0 + (mouseX / (float) width) * 16.0; 
  int x = int(random(a.width));
  int y = int(random(a.height));
  int loc = x + y*a.width;
  float r = red(a.pixels[loc]);
  float g = green(a.pixels[loc]);
  float b = blue(a.pixels[loc]);
  fill(r,g,b,126);
  ellipse(x,y,pointillize,pointillize);
}