c#实现识别图片上的验证码数字

public void imgdo(Bitmap img)
    {
      //去色
      Bitmap btp = img;
      Color c = new Color();
      int rr, gg, bb;
      for (int i = 0; i < btp.Width; i++)
      {
 for (int j = 0; j < btp.Height; j++)
 {
   //取图片当前的像素点
   c = btp.GetPixel(i, j);
   rr = c.R; gg = c.G; bb = c.B;
   //改变颜色
   if (rr == 102 && gg == 0 && bb == 0)
   {
     //重新设置当前的像素点
     btp.SetPixel(i, j, Color.FromArgb(255, 255, 255, 255));
   }
   if (rr == 153 && gg == 0 && bb == 0)
   {
     //重新设置当前的像素点
     btp.SetPixel(i, j, Color.FromArgb(255, 255, 255, 255));
   } if (rr == 153 && gg == 0 && bb == 51)
   {
     //重新设置当前的像素点
     btp.SetPixel(i, j, Color.FromArgb(255, 255, 255, 255));
   } if (rr == 153 && gg == 43 && bb == 51)
   {
     //重新设置当前的像素点
     btp.SetPixel(i, j, Color.FromArgb(255, 255, 255, 255));
   }
   if (rr == 255 && gg == 255 && bb == 0)
   {
     //重新设置当前的像素点
     btp.SetPixel(i, j, Color.FromArgb(255, 255, 255, 255));
   }
   if (rr == 255 && gg == 255 && bb == 51)
   {
     //重新设置当前的像素点
     btp.SetPixel(i, j, Color.FromArgb(255, 255, 255, 255));
   }
 }
      }
      btp.Save("d:\去除相关颜色.png");
 
      pictureBox2.Image = Image.FromFile("d:\去除相关颜色.png");
 
 
      //灰度
      Bitmap bmphd = btp;
      for (int i = 0; i < bmphd.Width; i++)
      {
 for (int j = 0; j < bmphd.Height; j++)
 {
   //取图片当前的像素点
   var color = bmphd.GetPixel(i, j);
 
   var gray = (int)(color.R * 0.001 + color.G * 0.700 + color.B * 0.250);
 
   //重新设置当前的像素点
   bmphd.SetPixel(i, j, Color.FromArgb(gray, gray, gray));
 }
      }
      bmphd.Save("d:\灰度.png");
      pictureBox27.Image = Image.FromFile("d:\灰度.png");
 
 
      //二值化
      Bitmap erzhi = bmphd;
      Bitmap orcbmp;
      int nn = 3;
      int w = erzhi.Width;
      int h = erzhi.Height;
      BitmapData data = erzhi.LockBits(new Rectangle(0, 0, w, h), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
      unsafe
      {
 byte* p = (byte*)data.Scan0;
 byte[,] vSource = new byte[w, h];
 int offset = data.Stride - w * nn;
 
 for (int y = 0; y < h; y++)
 {
   for (int x = 0; x < w; x++)
   {
     vSource[x, y] = (byte)(((int)p[0] + (int)p[1] + (int)p[2]) / 3);
     p += nn;
   }
   p += offset;
 }
 erzhi.UnlockBits(data);
 
 Bitmap bmpDest = new Bitmap(w, h, PixelFormat.Format24bppRgb);
 BitmapData dataDest = bmpDest.LockBits(new Rectangle(0, 0, w, h), ImageLockMode.WriteOnly, PixelFormat.Format24bppRgb);
 p = (byte*)dataDest.Scan0;
 offset = dataDest.Stride - w * nn;
 for (int y = 0; y < h; y++)
 {
   for (int x = 0; x < w; x++)
   {
     p[0] = p[1] = p[2] = (int)vSource[x, y] > 161 ? (byte)255 : (byte)0;
     //p[0] = p[1] = p[2] = (int)GetAverageColor(vSource, x, y, w, h) > 50 ? (byte)255 : (byte)0;
     p += nn;
 
   }
   p += offset;
 }
 bmpDest.UnlockBits(dataDest);
  
 orcbmp = bmpDest;
 orcbmp.Save("d:\二值化.png");
 pictureBox29.Image = Image.FromFile("d:\二值化.png");
      }
 
      //OCR的值
      if (orcbmp != null)
      {
 string result = Ocr(orcbmp);
 label32.Text = result.Replace("n", "rn").Replace(" ", "");
      }
 
    }

C#识别验证码图片通用类

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
 
namespace BallotAiying2
{
  class UnCodebase
  {
    public Bitmap bmpobj;
    public UnCodebase(Bitmap pic)
    {
      bmpobj = new Bitmap(pic);  //转换为Format32bppRgb
    }
 
    /// 

    /// 根据RGB，计算灰度值
    /// 
    /// Color值
    /// 灰度值，整型
    private int GetGrayNumColor(System.Drawing.Color posClr)
    {
      return (posClr.R * 19595 + posClr.G * 38469 + posClr.B * 7472) >> 16;
    }
 
    /// 

    /// 灰度转换,逐点方式
    /// 
    public void GrayByPixels()
    {
      for (int i = 0; i < bmpobj.Height; i++)
      {
 for (int j = 0; j < bmpobj.Width; j++)
 {
   int tmpValue = GetGrayNumColor(bmpobj.GetPixel(j, i));
   bmpobj.SetPixel(j, i, Color.FromArgb(tmpValue, tmpValue, tmpValue));
 }
      }
    }
 
    /// 

    /// 去图形边框
    /// 
    /// 
    public void ClearPicBorder(int borderWidth)
    {
      for (int i = 0; i < bmpobj.Height; i++)
      {
 for (int j = 0; j < bmpobj.Width; j++)
 {
   if (i < borderWidth || j < borderWidth || j > bmpobj.Width - 1 - borderWidth || i > bmpobj.Height - 1 - borderWidth)
     bmpobj.SetPixel(j, i, Color.FromArgb(255, 255, 255));
 }
      }
    }
 
    /// 

    /// 灰度转换,逐行方式
    /// 
    public void GrayByLine()
    {
      Rectangle rec = new Rectangle(0, 0, bmpobj.Width, bmpobj.Height);
      BitmapData bmpData = bmpobj.LockBits(rec, ImageLockMode.ReadWrite, bmpobj.PixelFormat);// PixelFormat.Format32bppPArgb);
      //  bmpData.PixelFormat = PixelFormat.Format24bppRgb;
      IntPtr scan0 = bmpData.Scan0;
      int len = bmpobj.Width * bmpobj.Height;
      int[] pixels = new int[len];
      Marshal.Copy(scan0, pixels, 0, len);
 
      //对图片进行处理
      int GrayValue = 0;
      for (int i = 0; i < len; i++)
      {
 GrayValue = GetGrayNumColor(Color.FromArgb(pixels));
 pixels = (byte)(Color.FromArgb(GrayValue, GrayValue, GrayValue)).ToArgb();   //Color转byte
      }
 
      bmpobj.UnlockBits(bmpData);
    }
 
    /// 

    /// 得到有效图形并调整为可平均分割的大小
    /// 
    /// 灰度背景分界值
    /// 有效字符数
    /// 
    public void GetPicValidByValue(int dgGrayValue, int CharsCount)
    {
      int posx1 = bmpobj.Width; int posy1 = bmpobj.Height;
      int posx2 = 0; int posy2 = 0;
      for (int i = 0; i < bmpobj.Height; i++)   //找有效区
      {
 for (int j = 0; j < bmpobj.Width; j++)
 {
   int pixelValue = bmpobj.GetPixel(j, i).R;
   if (pixelValue < dgGrayValue)   //根据灰度值
   {
     if (posx1 > j) posx1 = j;
     if (posy1 > i) posy1 = i;
 
     if (posx2 < j) posx2 = j;
     if (posy2 < i) posy2 = i;
   };
 };
      };
      // 确保能整除
      int Span = CharsCount - (posx2 - posx1 + 1) % CharsCount;  //可整除的差额数
      if (Span < CharsCount)
      {
 int leftSpan = Span / 2;  //分配到左边的空列 ，如span为单数,则右边比左边大1
 if (posx1 > leftSpan)
   posx1 = posx1 - leftSpan;
 if (posx2 + Span - leftSpan < bmpobj.Width)
   posx2 = posx2 + Span - leftSpan;
      }
      //复制新图
      Rectangle cloneRect = new Rectangle(posx1, posy1, posx2 - posx1 + 1, posy2 - posy1 + 1);
      bmpobj = bmpobj.Clone(cloneRect, bmpobj.PixelFormat);
    }
     
    /// 

    /// 得到有效图形,图形为类变量
    /// 
    /// 灰度背景分界值
    /// 有效字符数
    /// 
    public void GetPicValidByValue(int dgGrayValue)
    {
      int posx1 = bmpobj.Width; int posy1 = bmpobj.Height;
      int posx2 = 0; int posy2 = 0;
      for (int i = 0; i < bmpobj.Height; i++)   //找有效区
      {
 for (int j = 0; j < bmpobj.Width; j++)
 {
   int pixelValue = bmpobj.GetPixel(j, i).R;
   if (pixelValue < dgGrayValue)   //根据灰度值
   {
     if (posx1 > j) posx1 = j;
     if (posy1 > i) posy1 = i;
 
     if (posx2 < j) posx2 = j;
     if (posy2 < i) posy2 = i;
   };
 };
      };
      //复制新图
      Rectangle cloneRect = new Rectangle(posx1, posy1, posx2 - posx1 + 1, posy2 - posy1 + 1);
      bmpobj = bmpobj.Clone(cloneRect, bmpobj.PixelFormat);
    }
 
    /// 

    /// 得到有效图形,图形由外面传入
    /// 
    /// 灰度背景分界值
    /// 有效字符数
    /// 
    public Bitmap GetPicValidByValue(Bitmap singlepic, int dgGrayValue)
    {
      int posx1 = singlepic.Width; int posy1 = singlepic.Height;
      int posx2 = 0; int posy2 = 0;
      for (int i = 0; i < singlepic.Height; i++)   //找有效区
      {
 for (int j = 0; j < singlepic.Width; j++)
 {
   int pixelValue = singlepic.GetPixel(j, i).R;
   if (pixelValue < dgGrayValue)   //根据灰度值
   {
     if (posx1 > j) posx1 = j;
     if (posy1 > i) posy1 = i;
 
     if (posx2 < j) posx2 = j;
     if (posy2 < i) posy2 = i;
   };
 };
      };
      //复制新图
      Rectangle cloneRect = new Rectangle(posx1, posy1, posx2 - posx1 + 1, posy2 - posy1 + 1);
      return singlepic.Clone(cloneRect, singlepic.PixelFormat);
    }
     
    /// 

    /// 平均分割图片
    /// 
    /// 水平上分割数
    /// 垂直上分割数
    /// 分割好的图片数组
    public Bitmap [] GetSplitPics(int RowNum,int ColNum)
    {
      if (RowNum == 0 || ColNum == 0)
 return null;
      int singW = bmpobj.Width / RowNum;
      int singH = bmpobj.Height / ColNum;
      Bitmap [] PicArray=new Bitmap[RowNum*ColNum];
 
      Rectangle cloneRect;
      for (int i = 0; i < ColNum; i++)   //找有效区
      {
 for (int j = 0; j < RowNum; j++)
 {
   cloneRect = new Rectangle(j*singW, i*singH, singW , singH);
   PicArray[i*RowNum+j]=bmpobj.Clone(cloneRect, bmpobj.PixelFormat);//复制小块图
 }
      }
      return PicArray;
    }
 
    /// 

    /// 返回灰度图片的点阵描述字串，1表示灰点，0表示背景
    /// 
    /// 灰度图
    /// 背前景灰色界限
    /// 
    public string GetSingleBmpCode(Bitmap singlepic, int dgGrayValue)
    {
      Color piexl;
      string code = "";
      for (int posy = 0; posy < singlepic.Height; posy++)
 for (int posx = 0; posx < singlepic.Width; posx++)
 {
   piexl = singlepic.GetPixel(posx, posy);
   if (piexl.R < dgGrayValue)  // Color.Black )
     code = code + "1";
   else
     code = code + "0";
 }
      return code;
    }
  }
}

以上2则都是使用C#实现的orc识别的代码，希望对大家学习C#有所帮助。