C# 如何在一张大图片中快速找到另外一张图片（两种方式）？

　　　　　　　var findpic = new FindPic();             var rec = findpic.FindPicture(@"C:UserszaranetDesktopxiao.png", @"C:UserszaranetDesktopda.png", 10);             MessageBox.Show(rec[0].X +","+rec[0].Y);

    class FindPic     {         #region 找图         /// <summary>         /// 查找图片，不能镂空         /// </summary>         /// <param name="subPic">要查找坐标的小图</param>         /// <param name="parPic">在哪个大图里查找</param>         /// <param name="errorRange">容错，单个色值范围内视为正确0~255</param>         /// <param name="searchRect">如果为empty，则默认查找整个图像</param>         /// <param name="matchRate">图片匹配度，默认90%</param>         /// <param name="isFindAll">是否查找所有相似的图片</param>         /// <returns>返回查找到的图片的中心点坐标</returns>         public List<System.Drawing.Point> FindPicture(string subPic, string parPic, byte errorRange = 0, Rectangle searchRect = new System.Drawing.Rectangle(), double matchRate = 0.9, bool isFindAll = false)         {             List<System.Drawing.Point> ListPoint = new List<System.Drawing.Point>();             var subBitmap = new Bitmap(subPic);             var parBitmap = new Bitmap(parPic);             int subWidth = subBitmap.Width;             int subHeight = subBitmap.Height;             int parWidth = parBitmap.Width;             int parHeight = parBitmap.Height;             if (searchRect.IsEmpty)             {                 searchRect = new Rectangle(0, 0, parBitmap.Width, parBitmap.Height);             }             var searchLeftTop = searchRect.Location;             var searchSize = searchRect.Size;             System.Drawing.Color startPixelColor = subBitmap.GetPixel(0, 0);             var subData = subBitmap.LockBits(new Rectangle(0, 0, subBitmap.Width, subBitmap.Height), ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);             var parData = parBitmap.LockBits(new Rectangle(0, 0, parBitmap.Width, parBitmap.Height), ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);             var byteArrarySub = new byte[subData.Stride * subData.Height];             var byteArraryPar = new byte[parData.Stride * parData.Height];             Marshal.Copy(subData.Scan0, byteArrarySub, 0, subData.Stride * subData.Height);             Marshal.Copy(parData.Scan0, byteArraryPar, 0, parData.Stride * parData.Height);             var iMax = searchLeftTop.Y + searchSize.Height - subData.Height;//行             var jMax = searchLeftTop.X + searchSize.Width - subData.Width;//列             int smallOffsetX = 0, smallOffsetY = 0;             int smallStartX = 0, smallStartY = 0;             int pointX = -1; int pointY = -1;             for (int i = searchLeftTop.Y; i < iMax; i++)             {                 for (int j = searchLeftTop.X; j < jMax; j++)                 {                     //大图x，y坐标处的颜色值                     int x = j, y = i;                     int parIndex = i * parWidth * 4 + j * 4;                     var colorBig = System.Drawing.Color.FromArgb(byteArraryPar[parIndex + 3], byteArraryPar[parIndex + 2], byteArraryPar[parIndex + 1], byteArraryPar[parIndex]);                     ;                     if (ColorAEqualColorB(colorBig, startPixelColor, errorRange))                     {                         smallStartX = x - smallOffsetX;//待找的图X坐标                         smallStartY = y - smallOffsetY;//待找的图Y坐标                         int sum = 0;//所有需要比对的有效点                         int matchNum = 0;//成功匹配的点                         for (int m = 0; m < subHeight; m++)                         {                             for (int n = 0; n < subWidth; n++)                             {                                 int x1 = n, y1 = m;                                 int subIndex = m * subWidth * 4 + n * 4;                                 var color = System.Drawing.Color.FromArgb(byteArrarySub[subIndex + 3], byteArrarySub[subIndex + 2], byteArrarySub[subIndex + 1], byteArrarySub[subIndex]);                                 sum++;                                 int x2 = smallStartX + x1, y2 = smallStartY + y1;                                 int parReleativeIndex = y2 * parWidth * 4 + x2 * 4;//比对大图对应的像素点的颜色                                 var colorPixel = System.Drawing.Color.FromArgb(byteArraryPar[parReleativeIndex + 3], byteArraryPar[parReleativeIndex + 2], byteArraryPar[parReleativeIndex + 1], byteArraryPar[parReleativeIndex]);                                 if (ColorAEqualColorB(colorPixel, color, errorRange))                                 {                                     matchNum++;                                 }                             }                         }                         if ((double)matchNum / sum >= matchRate)                         {                             Console.WriteLine((double)matchNum / sum);                             pointX = smallStartX + (int)(subWidth / 2.0);                             pointY = smallStartY + (int)(subHeight / 2.0);                             var point = new System.Drawing.Point(pointX, pointY);                             if (!ListContainsPoint(ListPoint, point, 10))                             {                                 ListPoint.Add(point);                             }                             if (!isFindAll)                             {                                 goto FIND_END;                             }                         }                     }                     //小图x1,y1坐标处的颜色值                 }             }         FIND_END:             subBitmap.UnlockBits(subData);             parBitmap.UnlockBits(parData);             subBitmap.Dispose();             parBitmap.Dispose();             GC.Collect();             return ListPoint;         }         #endregion         public bool ColorAEqualColorB(System.Drawing.Color colorA, System.Drawing.Color colorB, byte errorRange = 10)         {             return colorA.A <= colorB.A + errorRange && colorA.A >= colorB.A - errorRange &&                 colorA.R <= colorB.R + errorRange && colorA.R >= colorB.R - errorRange &&                 colorA.G <= colorB.G + errorRange && colorA.G >= colorB.G - errorRange &&                 colorA.B <= colorB.B + errorRange && colorA.B >= colorB.B - errorRange;         }         public bool ListContainsPoint(List<System.Drawing.Point> listPoint, System.Drawing.Point point, double errorRange = 10)         {             bool isExist = false;             foreach (var item in listPoint)             {                 if (item.X <= point.X + errorRange && item.X >= point.X - errorRange && item.Y <= point.Y + errorRange && item.Y >= point.Y - errorRange)                 {                     isExist = true;                 }             }             return isExist;         }     }

private void button3_Click(object sender, EventArgs e)         {             System.Drawing.Bitmap sourceImage = ConvertToFormat(System.Drawing.Image.FromFile(@"C:UserszaranetDesktopda.png"), PixelFormat.Format24bppRgb);             System.Drawing.Bitmap template = ConvertToFormat(System.Drawing.Image.FromFile(@"C:UserszaranetDesktopxiao.png"), PixelFormat.Format24bppRgb);              // create template matching algorithm's instance             // (set similarity threshold to 92.5%)              ExhaustiveTemplateMatching tm = new ExhaustiveTemplateMatching(0.921f);             // find all matchings with specified above similarity              TemplateMatch[] matchings = tm.ProcessImage(sourceImage, template);             // highlight found matchings              BitmapData data = sourceImage.LockBits(                 new Rectangle(0, 0, sourceImage.Width, sourceImage.Height),                 ImageLockMode.ReadWrite, sourceImage.PixelFormat);             foreach (TemplateMatch m in matchings)             {                  Drawing.Rectangle(data, m.Rectangle, Color.White);                  MessageBox.Show(m.Rectangle.Location.ToString());                 // do something else with matching             }             sourceImage.UnlockBits(data);         }         public Bitmap ConvertToFormat(System.Drawing.Image image, PixelFormat format)         {             Bitmap copy = new Bitmap(image.Width, image.Height, format);             using (Graphics gr = Graphics.FromImage(copy))             {                 gr.DrawImage(image, new Rectangle(0, 0, copy.Width, copy.Height));             }             return copy;         }