参考：http://www.cnblogs.com/yuanbao/archive/2007/09/25/905322.html
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[i]));
pixels[i] = (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;
}
}
}