c#实现识别图片上的验证码数字

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。