验证码识别技术研究（2）

/// <summary>
        /// 获取主体矩形边界坐标，顺时针
        /// </summary>
        /// <param name="bmpTg">目标图片</param>
        /// <param name="bmpMT">模板图片</param>
        /// <returns></returns>
        private static Point[] GetTarget(Bitmap bmpTg, Bitmap bmpMT)
        {
            //主体矩形边界坐标,顺时针
            Point[] points ={
                new Point(0,0),
                new Point(0,0),
                new Point(0,0),
                new Point(0,0),
                           };

            int tmpRGB = 0;
            for (int tgx = 0; tgx < bmpTg.Width - bmpMT.Width; tgx++)
            {
                for (int tgy = 0; tgy < bmpTg.Height - bmpMT.Height; tgy++)
                {
                    bool faild = false;
                    for (int mtx = 0; mtx < bmpMT.Width; mtx++)
                    {
                        for (int mty = 0; mty < bmpMT.Height; mty++)
                        {
                            if (bmpMT.GetPixel(mtx, mty).B > 150)
                                continue;
                            tmpRGB = bmpTg.GetPixel(tgx + mtx, tgy + mty).B - bmpMT.GetPixel(mtx, mty).B;
                            tmpRGB = tmpRGB > 0 ? tmpRGB : tmpRGB * (-1);
                            if (tmpRGB > 150)
                            {
                                faild = true;
                                continue;
                            }
                        }
                    }
                    if (faild)
                    {
                        continue;
                    }
                    points[0].X = tgx;
                    points[0].Y = tgy;
                    points[1].X = tgx + bmpMT.Width;
                    points[1].Y = tgy;
                    points[2].X = tgx;
                    points[2].Y = tgy + bmpMT.Height;
                    points[3].X = tgx + bmpMT.Width;
                    points[3].Y = tgy + bmpMT.Height;
                    return points;
                }
            }
            return points;
        }