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", "\r\n").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
    }
 
    /// <summary>
    /// 根据rgb，计算灰度值
    /// </summary>
    /// <param name="posclr">color值</param>
    /// <returns>灰度值，整型</returns>
    private int getgraynumcolor(system.drawing.color posclr)
    {
      return (posclr.r * 19595 + posclr.g * 38469 + posclr.b * 7472) >> 16;
    }
 
    /// <summary>
    /// 灰度转换,逐点方式
    /// </summary>
    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));
        }
      }
    }
 
    /// <summary>
    /// 去图形边框
    /// </summary>
    /// <param name="borderwidth"></param>
    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));
        }
      }
    }
 
    /// <summary>
    /// 灰度转换,逐行方式
    /// </summary>
    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);
    }
 
    /// <summary>
    /// 得到有效图形并调整为可平均分割的大小
    /// </summary>
    /// <param name="dggrayvalue">灰度背景分界值</param>
    /// <param name="charscount">有效字符数</param>
    /// <returns></returns>
    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);
    }
     
    /// <summary>
    /// 得到有效图形,图形为类变量
    /// </summary>
    /// <param name="dggrayvalue">灰度背景分界值</param>
    /// <param name="charscount">有效字符数</param>
    /// <returns></returns>
    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);
    }
 
    /// <summary>
    /// 得到有效图形,图形由外面传入
    /// </summary>
    /// <param name="dggrayvalue">灰度背景分界值</param>
    /// <param name="charscount">有效字符数</param>
    /// <returns></returns>
    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);
    }
     
    /// <summary>
    /// 平均分割图片
    /// </summary>
    /// <param name="rownum">水平上分割数</param>
    /// <param name="colnum">垂直上分割数</param>
    /// <returns>分割好的图片数组</returns>
    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;
    }
 
    /// <summary>
    /// 返回灰度图片的点阵描述字串，1表示灰点，0表示背景
    /// </summary>
    /// <param name="singlepic">灰度图</param>
    /// <param name="dggrayvalue">背前景灰色界限</param>
    /// <returns></returns>
    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。