/**
Sparkles by <a href="http://www.local-guru.net/blog">guru</a>
*/
PImage img;

void setup() {
  img = loadImage( "glitzer.jpg" );
  size(600,400);
}

void draw() {
  image( img, 0, 0 );
  stroke(255, 130);
  int l = img.pixels.length;
  for( int i = 0; i < l; i++) {
    float b = brightness(img.pixels[i]);
    if (b > 253) {
      int x = i%width;
      int y = i/width;
      float f = (255 - b) * 3;
      if ( random( 100 ) > 60 ) {
        stroke( 255, 200);
      } else {
        stroke( 255, 100);
      }
     line( x - f, y - f, x + f, y + f );
     line( x - f, y + f, x + f, y - f );
    }
  }
}