C#验证码识别类完整实例

本文实例讲述了C#验证码识别类。分享给大家供大家参考。具体实现方法如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
namespace 验证码处理
{
 class VerifyCode
 {
  public Bitmap bmpobj;
  public VerifyCode(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[i]));
    pixels[i] = (byte)(Color.FromArgb(GrayValue, GrayValue, GrayValue)).ToArgb();  //Color转byte
   }
   bmpobj.UnlockBits(bmpData);
   ////输出
   //GCHandle gch = GCHandle.Alloc(pixels, GCHandleType.Pinned);
   //bmpOutput = new Bitmap(bmpobj.Width, bmpobj.Height, bmpData.Stride, bmpData.PixelFormat, gch.AddrOfPinnedObject());
   //gch.Free();
  }
  /// <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;
  }
  /// <summary>
  /// 得到灰度图像前景背景的临界值 最大类间方差法
  /// </summary>
  /// <returns>前景背景的临界值</returns>
  public int GetDgGrayValue()
  {
   int[] pixelNum = new int[256];   //图象直方图，共256个点
   int n, n1, n2;
   int total;        //total为总和，累计值
   double m1, m2, sum, csum, fmax, sb;  //sb为类间方差，fmax存储最大方差值
   int k, t, q;
   int threshValue = 1;      // 阈值
   //