@Override
                protected BufferedImage doInBackground() throws Exception {
                    long starttime = System.nanoTime();
                    BufferedImage image = new BufferedImage(AREAX, AREAY, BufferedImage.TYPE_INT_RGB);
                    Graphics g = image.createGraphics();
                    double dpcnt; //Delta percent
                    dpcnt = 99.99 / AREAY;
                    percnt = 0;
                    Dx = (REEL_MAX - REEL_MIN) / AREAX;
                    Dy = (IMAG_MAX - IMAG_MIN) / AREAY;
                    //Dx = -0.00357142857142857142857142857143;
                    //Dy = -0.00357142857142857142857142857143;
                    double x = REEL_MIN;
                    double y = IMAG_MIN;
                    for (int i = 0; i < AREAY; i++) {
                        percnt = percnt + dpcnt;
                        for (int j = 0; j < AREAX; j++) {
                            int count = 0;
                            double p0 = x;
                            double q0 = y;
                            double LIMIT = 20.0;
                            for (int k = 0; Math.abs(p0) <= LIMIT && Math.abs(q0) <= LIMIT && k < LOOP_LIMIT; k++) {
                                double p1 = p0 * p0 - q0 * q0 + x;
                                double q1 = 2 * p0 * q0 + y;
                                p0 = p1;
                                q0 = q1;
                                count++;
                            }
                            if (Math.abs(p0) < LIMIT && Math.abs(q0) < LIMIT) {
                                g.setColor(Color.black);
                            } else {
                                //g.setColor(farve);
                                g.setColor(AdvColorPix(count));
                            }
                            g.drawLine(j, i, j, i);
                            x = x + Dx;
                        }
                        x = REEL_MIN;
                        y = y + Dy;
                    }
                    System.out.println("Time to render: " + ((System.nanoTime() - starttime) / 1000) + " μs");
                    percnt = 100.0;
                    return image;
                }