y2 = 180;
                                }
                                else
                                {
                                    x2 = 180;
                                    y2 = Convert.ToInt16(180 * k + b);
                                }
                            }
                            else if (b < 0)
                            {
                                x1 = Convert.ToInt16(-b / k);
                                y1 = 0;
                                double temp = k * 180 + b;
                                if (temp >= 0 && temp <= 180)
                                {
                                    x2 = 180;
                                    y2 = Convert.ToInt16(temp);
                                }
                                else
                                { 彩色图像的分割处理程序设计+Hough算法(20):http://www.youerw.com/jisuanji/lunwen_1067.html