On Android Device Animation too slow! (on PC its normal) GPU? OpenGL?

I followed a tutorial from

And the Code runs very well in PC(Laptop).(It runs fluently)

But when I tried to run it on Android Device it became very slow. (i guess one frame / 2 Seconds) The Core Code is here

void draw() {
  background(51);

  loadPixels();
  for (int x = 0; x < width; x++) {
    for (int y = 0; y < height; y++) {
      int index = x + y * width;
      float sum = 0;
      for (Blob b : blobs) {
        float d = dist(x, y, b.pos.x, b.pos.y);
        sum += 10 * b.r / d;
      }
      pixels[index] = color(sum, 255, 255);
    }
  }

  updatePixels();

  for (Blob b : blobs) {
    b.update();
  }
}

Can anyone help me, what is the problem here?

Because it loads every pixel and does pixel processing, so it uses CPU? How can I do pixel Processing using GPU?(I am not sure, if i express this correctly, i have no experience in computer graphics)

Thanks