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分类： C/C++
2013-05-05 21:33:55
下面是一段C#写成的程序，里面用到了一些技巧，其实做过的人都知道，不太清楚的看一下代码，注释都给出来了，很好理解的。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.IO;
using System.Configuration;
namespace ConsoleApplication4
{
///
/// 根据样本做验证码破解
///
/// 需要在.config文件中的appSettings配置节中添加key为sampleOcr.sampleDir value设置为样本图片所在路径
/// 验证码：
///
/// outofmemory.cn 20120427
/// 100个样例准确数为88个，错误主要发生在389这三个字符的混淆上
///
public abstract class SampleOcr
{
///
/// 灰度中间值
///
static int MiddleGrayValue =200;
///
/// 分割图片的差异容忍度
///
static int ColorToleranceForSplit = 30;
///
/// 样本字典
///
static Dictionary
///
/// 破解验证码
///
/// 验证码图片
///
public static string Ocr(Bitmap bm)
{
//做灰度处理
GrayByPixels(bm);
bm =RemoveVerticalSpaceRegion(bm);
Bitmap[] splitBms =SplitBitmaps(bm);
char[] result = newchar[splitBms.Length];
for (int i = 0; i
{
result[i] =OcrChar(splitBms[i]);
splitBms[i].Dispose();
}
return new string(result);
}
///
/// 分割图片
///
/// 图片
///
static Bitmap[] SplitBitmaps(Bitmap bm)
{
//找出垂直分割线
List
for (int x = 0; x
{
bool hasDiffPoint =false;
Color color =Color.White;
for (int y = 0; y
{
if (y == 0)
{
color =bm.GetPixel(x, y);
}
else
{
Color currentColor = bm.GetPixel(x,y);
int diff =CalculateColorDifference(currentColor, color);
if (diff >ColorToleranceForSplit)
{
hasDiffPoint = true;
break;
}
// color =currentColor;
}
}
if (!hasDiffPoint)
{
removeXs.Add(x);
}
}
//根据空白区域，计算各个字符的位图
List
for (int i = 1; i
{
int diff = removeXs[i] -removeXs[i - 1];
if (diff > 5)
{
if (diff >= 20)
{
Rectangle rect = newRectangle(removeXs[i - 1], 0, diff / 2, bm.Height);
charRects.Add(rect);
rect = newRectangle(removeXs[i - 1] + diff / 2, 0, diff / 2, bm.Height);
charRects.Add(rect);
}
else
{
Rectangle rect =new Rectangle(removeXs[i - 1], 0, diff, bm.Height);
charRects.Add(rect);
}
}
}
int count =charRects.Count;
Bitmap[] charBms = newBitmap[count];
int charBmIndex = 0;
foreach (Rectangle item incharRects)
{
Bitmap bmChar =bm.Clone(item, bm.PixelFormat);
charBms[charBmIndex] =bmChar;
charBmIndex += 1;
}
return charBms;
}
///
/// 解析字符
///
/// 分割后的小图
///
static char OcrChar(Bitmap bm)
{
Dictionary
double diff = .0;
string mayBe = null;
foreach (string key insamples.Keys)
{
double diffRate =CalcImageDiffRate(samples[key], bm);
if (diffRate == 1)
return key[0];
if (diffRate >diff)
{
mayBe = key;
diff = diffRate;
}
}
if (mayBe == null) throw newApplicationException();
return mayBe[0];
}
///
/// 载入样本字典
///
///
private static Dictionary
{
if (_samples == null)
{
_samples = newDictionary
string sampleDir =ConfigurationManager.AppSettings["sampleOcr.sampleDir"] ??@"D:\SampleOcr\samples";
DirectoryInfo dirInfo = newDirectoryInfo(sampleDir);
FileInfo[] files =dirInfo.GetFiles("*.jpg");
foreach (FileInfo item in files)
{
Bitmap bm =(Bitmap)Bitmap.FromFile(item.FullName);
string key =Path.GetFileNameWithoutExtension(item.FullName);
_samples.Add(key,bm);
}
}
return _samples;
}
///
/// 根据RGB，计算灰度值
///
/// Color值
///
static 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
///
static void GrayByPixels(Bitmap bm)
{
for (int i = 0; i
{
for (int j = 0; j
{
int tmpValue =GetGrayNumColor(bm.GetPixel(j, i));
bm.SetPixel(j, i,Color.FromArgb(tmpValue, tmpValue, tmpValue));
}
}
}
///
/// 删除垂直方向上的空白区域
///
/// 源图片
///
static Bitmap RemoveVerticalSpaceRegion(Bitmap bm)
{
int topSpaceHeight = 0;
for (int y = 0; y
{
bool hasDiffPoint =false;
Color color =Color.White;
for (int x = 0; x
{
if (x == 0)
{
color =bm.GetPixel(x, y);
}
else
{
Color currentColor= bm.GetPixel(x, y);
int diff =CalculateColorDifference(currentColor, color);
if (diff >ColorToleranceForSplit)
{
hasDiffPoint =true;
break;
}
}
}
if (hasDiffPoint)
{
break;
}
else
{
topSpaceHeight +=1;
}
}
int bottomSpaceHeight = 0;
for (int y = bm.Height - 1; y> 0; y--)
{
bool hasDiffPoint =false;
Color color =Color.White;
for (int x = 0; x
{
if (x == 0)
{
color =bm.GetPixel(x, y);
}
else
{
Color currentColor= bm.GetPixel(x, y);
int diff =CalculateColorDifference(currentColor, color);
if (diff >ColorToleranceForSplit)
{
hasDiffPoint =true;
break;
}
color =currentColor;
}
}
if (hasDiffPoint)
{
break;
}
else
{
bottomSpaceHeight +=1;
}
}
Rectangle rectValid = newRectangle(0, topSpaceHeight, bm.Width, bm.Height - topSpaceHeight -bottomSpaceHeight);
Bitmap newBm =bm.Clone(rectValid, bm.PixelFormat);
bm.Dispose();
return newBm;
}
private static double CalcImageDiffRate(Bitmap bmSample, BitmapbmCalc)
{
int[] eSample = newint[bmSample.Height];
int[] eCalc = newint[bmSample.Height];
for (int y = 0; y
{
eSample[y] =GetHorizontalValue(bmSample, y);
eCalc[y] =GetHorizontalValue(bmCalc, y);
}
return GetCosine(eSample,eCalc);
}
///
/// 获得向量的cos值
///
///
///
///
static double GetCosine(int[] e1, int[] e2)
{
double fenzi = 0;
for (int i = 0; i
{
fenzi += e1[i] *e2[i];
}
double fenmuLeft = 0;
double fenmuRight = 0;
for (int i = 0; i
{
fenmuLeft += e1[i] *e1[i];
fenmuRight += e2[i] *e2[i];
}
double fenmu =Math.Sqrt(fenmuLeft) * Math.Sqrt(fenmuRight);
if (fenmu == 0.0) return0;
return fenzi / fenmu;
}
///
/// 计算水平方向上的差异点数
///
/// 位图
/// y坐标值
///
private static int GetHorizontalValue(Bitmap bm, int y)
{
if (y >= bm.Height) return0;
int val = 0;
for (int x = 0; x
{
Color color =bm.GetPixel(x, y);
int grayVal =GetColorGrayValue(color);
if (grayVal >MiddleGrayValue)
{
val |= (1 <
}
}
return val;
}
static int GetColorGrayValue(Color color)
{
return (int)(.299 * color.R +.587 * color.G + .114 * color.B);
}
///
/// 计算颜色之间的差值，这个只是一个简单的计算，真正的色差计算很复杂
///
/// A色
/// B色
///
static int CalculateColorDifference(Color colorA, Color colorB)
{
int diff =GetColorGrayValue(colorA) - GetColorGrayValue(colorB);
return Math.Abs(diff);
}
}
}
