Processing program to generate "halftone" pattern.

halftone.pde

void setup() {
  size(4096, 2048);
  // The background image must be the same size as the parameters
  // into the size() method. In this program, the size of the image
  // is 640 x 360 pixels.
  background(0);
  noStroke();
  noLoop();
}

int maxr = 32;
int mod = 1;

void draw() 
{
  int steps = 2048 / maxr / 2;
  float delta_r = maxr / steps * 1.5;
  float r = maxr * 1.5;
  for(int iy = 0; iy * maxr * 2 <= 2048; iy++)
  {
    for(int ix = 0; ix * maxr * 2 <= 4096; ix++)
    {
      if((ix + iy) % mod == 0)
      {
        ellipse(ix * maxr * 2, iy * maxr * 2, 2*r, 2*r);
      }
    }
    r -= delta_r;
  }
  save("halftone.png");
}