30行代码解析滑块验证码图片缺口的位置

有这样一种图片验证码

话不多说，直接上代码：

 /// <summary>
        /// 获取滑块图片水平缺口的位置
        /// </summary>
        /// <param name="bitmapA"></param>
        /// <returns></returns>
        public static int GetDiffPixel(Bitmap bitmapA)
        {
            for (int w = 0; w < bitmapA.Width - 10; w++)
            {
                int iDiffPix = 0;
                int iDiffPixMax = 0;
                for (int h = 0; h < bitmapA.Height; h++)
                {
                    Color piexl1 = bitmapA.GetPixel(w, h);
                    bool isCoherentH = true;
                    for (int i = 0; i < 10; i++)
                    {
                        Color piexl2 = bitmapA.GetPixel(w + i, h);
                        if (Math.Sqrt(3 * Math.Pow(Convert.ToDouble(piexl1.R) - Convert.ToDouble(piexl2.R), 2) + 4 * Math.Pow(Convert.ToDouble(piexl1.G) - Convert.ToDouble(piexl2.G), 2) + 2 * Math.Pow(Convert.ToDouble(piexl1.B) - Convert.ToDouble(piexl2.B), 2)) > 1)
                        {
                            isCoherentH = false;
                            break;
                        }
                    }
                    if (isCoherentH)
                    {
                        iDiffPix++;
                    }
                    else
                    {
                        iDiffPixMax = Math.Max(iDiffPix, iDiffPixMax);
                        iDiffPix = 0;
                    }
                }
                if (iDiffPixMax > 29)
                    return w - 10;
            }
            return 0;
        }