Simple processing program to generate checker patterns.

checkers.pde

int SIZE = 64;
int scale = 2;

void settings() {
  size(SIZE, SIZE); 
}

void setup() {
  color c1 = color(255);
  color c2 = color(0);
  
  loadPixels();
  for (int i = 0; i < width; i++) {
    for (int j = 0; j < height / scale; j++) {
      for (int k = 0; k < scale; k++) {
        int y = j * scale + k;
        int index = i + y * width;
        if (j % 2 == 0) {
          pixels[index] = i % (scale * 2) < scale ? c1 : c2;
        } else {
          pixels[index] = i % (scale * 2) < scale ? c2 : c1;
        }
      }
    }
  }
  
  updatePixels();
  
  save("checkers-" + SIZE + "-" + scale + ".png");
  exit();
}