C#驗證碼辨認基本辦法實例剖析。本站提示廣大學習愛好者：（C#驗證碼辨認基本辦法實例剖析）文章只能為提供參考，不一定能成為您想要的結果。以下是C#驗證碼辨認基本辦法實例剖析正文
本文實例講述了C#驗證碼辨認基本辦法，長短常適用的技能。分享給年夜家供年夜家參考。詳細辦法剖析以下：
配景
比來有同伙在弄一個器械，曾經做的挺不錯了，最初想再完善一點，因而乎就提議把這類驗證碼給K.O.了，因而乎就K.O.了這個驗證碼。到達單個圖片辨認時光小於200ms，500個樣自己工統計准確率為95%。因為自己沒有相干經歷，是摸著石頭過河。本著經歷分享的精力，分享一下全部剖析的思緒。在列位年夜神眼前獻丑了。
再來看看部門辨認成果以下圖所示：
這裡是否是看著很眼生？上面再來詳細剖析一下。
處置第一步 去配景樂音和二值化
關於這一塊，斟酌了幾種辦法。
辦法一：統計圖片色彩散布，色彩占領率低的剖斷為配景樂音。因為配景樂音和遠景色辨別其實不顯著，測驗考試了許多種取景辦法都不克不及很好去除配景樂音，終究廢棄了這類辦法。
辦法二：過後在網上略微查了下，比來比擬風行盤算灰度後設定一個阈值停止二值化。其實所謂的灰度圖片道理是依據人眼對顏色敏感度取了權值，這個權值對盤算機來講沒有甚麼意義。略微想一下便可以發明，這兩個進程完整可以歸並。因而乎我一步完成了去配景樂音和二值化。阈值設置為RGB三重量之和到500。成果異常使人滿足。
處置第二步 制造字符樣本
樣本關於盤算機來講長短常主要的，由於盤算機很難有邏輯思想，就算有邏輯思想也要經由歷久練習能力讓你滿足。所以要用事前制造好的樣本停止比擬。假如你細心不雅察過這些驗證碼會發明一個bug，簡直年夜部門的驗證碼都是應用異樣的字體，因而乎就人工制造了一套字體的樣本。因為上一步曾經有去除配景樂音的成果，可以直接應用。制造樣本這一步有點簡略死板，還須要仔細。能夠由於你的一個不仔細會招致某個符號的辨認率偏低。在這500個樣本中，只發明了31個字符。虧得是某部分的或人員還斟酌到了易錯的字符，例如，1和I，0和O等。要否則這個某部分要背負更多的罵名。
處置第三步 婚配
單個婚配用了最簡略最原始的二值比擬，不外婚配的是婚配率而不是婚配數。我界說了相干的計分准繩。年夜准繩是“該有的有了加分，該有的沒了減分，不應有的有了過度減分，可達區域外的不算分”。
因為一些符號的部門區域婚配成果跟另外一些符號的完全婚配成果類似，須要把單個婚配在一個擴展的區域內擇優。在必定的規模內，找到一個最好婚配，這個最好婚配就是以後地位對應的符號。
完成了一次最好婚配，可以把婚配地位向右推動一年夜步，若找不到適合的最好婚配就向右推動一小步。
處置第四步 優化和調劑
任何一個算法都是須要優化和調劑的。如今要找到最好參數設置裝備擺設和最好代碼組織。這一步常常是須要消費最多時光和精神的。
處置第五步 驗證成果
這一步呢，純人力驗證成果，統計出准確率。
思慮：
成果是出來了，代碼也不多，後果也很幻想。弄這一行的，許多時刻都想要通用的。可否通用，很年夜水平上在於籠統條理。本辦法只是純真的婚配，天然不克不及通用，然則辦法和思惟倒是通用的。詳細案例詳細剖析。至於歪曲文字、空心文字等，處置要龐雜的多。網上也有一些應用第三方圖象庫的辦法，或許那些辦法會比擬通用。等有空了有興致了持續弄一下這個主題。
實例源碼：
至於這個源碼要不要宣布，糾結了一段時光。網上曾經有相似的貿易運動了，並且這個辨認自己沒有太年夜難度，再加上某體系生成的bug，此驗證碼自己就相當於沒有設置，是以宣布此代碼，僅作於進修交換。
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.IO.Compression;
namespace Crack12306Captcha
{
public class Cracker
{
List<CharInfo> words_ = new List<CharInfo>();
public Cracker()
{
var bytes = new byte[] {
0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0xc5, 0x58, 0xd9, 0x92, 0x13, 0x31,
0x0c, 0x94, 0x9e, 0x93, 0x0c, 0x61, 0x97, 0x2f, 0xe1, 0x58, 0xe0, 0x91, 0x9b, 0x82, 0x62, 0x0b,
0x58, 0xee, 0xff, 0xff, 0x10, 0xd8, 0xcc, 0xc8, 0xea, 0x96, 0x6c, 0x8f, 0x13, 0x48, 0xe1, 0xaa,
0x4d, 0x46, 0x96, 0x6d, 0xb5, 0x8e, 0x96, 0x67, 0x73, 0x7f, 0x3b, 0x09, 0x0e, 0x25, 0x41, 0x49,
0xa3, 0xae, 0xd7, 0x5b, 0xa9, 0xa8, 0xd5, 0xb4, 0x76, 0x02, 0x6a, 0x5c, 0x52, 0x94, 0x54, 0xed,
0x18, 0x5a, 0x7f, 0x18, 0x00, 0x00, 0x84, 0x07, 0x1b, 0x80, 0x4a, 0x9a, 0x08, 0x35, 0xb8, 0x81,
0x50, 0xe7, 0xad, 0xbe, 0xc4, 0x8e, 0xb1, 0x4f, 0x2d, 0x5f, 0xba, 0x80, 0xbb, 0xfd, 0x9a, 0xad,
0x19, 0x36, 0xe5, 0xad, 0x87, 0xf1, 0x10, 0xc0, 0x8d, 0xc6, 0x50, 0x40, 0x52, 0xf8, 0xb3, 0x98,
0x2c, 0xd6, 0xec, 0x59, 0xe7, 0x0d, 0x3e, 0x0f, 0x93, 0x3e, 0x1d, 0x02, 0x7a, 0x18, 0x8f, 0xb6,
0xc7, 0x46, 0x4e, 0x01, 0xa3, 0x96, 0xdc, 0x3a, 0x20, 0x77, 0xbf, 0x2c, 0x24, 0xe4, 0x80, 0xa9,
0x20, 0x14, 0xe5, 0x2d, 0xb5, 0x68, 0xc9, 0x55, 0x89, 0x23, 0x96, 0x82, 0xaa, 0xba, 0x58, 0xa6,
0x03, 0x38, 0x71, 0x4b, 0x29, 0xd2, 0x47, 0x80, 0xe3, 0x84, 0x91, 0xf4, 0x78, 0x43, 0x64, 0x41,
0x7b, 0x73, 0x99, 0x80, 0x42, 0x48, 0x00, 0xde, 0x00, 0x12, 0x88, 0x80, 0xdb, 0x51, 0x4a, 0x49,
0x84, 0x43, 0xf6, 0x51, 0x90, 0x27, 0x21, 0xc9, 0xf8, 0xac, 0x00, 0x4d, 0xcd, 0x46, 0x09, 0x9d,
0x15, 0x78, 0xe0, 0x00, 0x1e, 0x44, 0x2a, 0x51, 0x8c, 0xbc, 0xd3, 0xa3, 0x68, 0x8a, 0xd5, 0x3a,
0x20, 0x79, 0xba, 0x4d, 0x71, 0x4c, 0x0b, 0x91, 0x98, 0x90, 0x7b, 0x2a, 0x42, 0xc5, 0x78, 0x7a,
0xfc, 0xd5, 0x1b, 0x4b, 0x09, 0xa7, 0x27, 0x99, 0x38, 0x05, 0x01, 0xc2, 0x80, 0x39, 0x9c, 0x67,
0xbb, 0x4e, 0x7f, 0x6c, 0x33, 0xdd, 0xed, 0x87, 0x55, 0xda, 0x5d, 0xb5, 0x56, 0x33, 0xc6, 0xf9,
0xea, 0x60, 0x64, 0xcf, 0xa7, 0x41, 0xe0, 0x5c, 0x1c, 0xc4, 0xb2, 0x25, 0xa3, 0x89, 0x88, 0x8d,
0x16, 0x00, 0xb5, 0xed, 0xa5, 0x22, 0x9d, 0x52, 0x41, 0x53, 0x8d, 0x92, 0x7f, 0x31, 0x51, 0x3f,
0xa8, 0x00, 0x85, 0x8a, 0x71, 0x10, 0x92, 0x78, 0xc4, 0x59, 0x08, 0x39, 0x69, 0xa9, 0x38, 0x41,
0x48, 0xf7, 0x40, 0x5a, 0x03, 0xd5, 0x3a, 0xf5, 0xe5, 0x9d, 0x33, 0x66, 0xc3, 0xd7, 0x1f, 0xef,
0x94, 0xa0, 0x53, 0xea, 0xf4, 0x15, 0xb2, 0x1c, 0x40, 0x2d, 0xcf, 0xaf, 0xce, 0xe9, 0xd4, 0x7a,
0x89, 0x09, 0xe6, 0xdd, 0xdb, 0x0e, 0xb8, 0x58, 0xa7, 0x60, 0x37, 0xfd, 0xf2, 0xfa, 0x2c, 0x4e,
0x51, 0x87, 0x0d, 0xfc, 0x16, 0x72, 0x2a, 0x5f, 0xc0, 0x80, 0xf0, 0x54, 0xa7, 0xde, 0xfc, 0x15,
0x8b, 0x9a, 0x36, 0x3a, 0x2c, 0x62, 0xfc, 0xd4, 0x8c, 0x31, 0xb7, 0xea, 0xd7, 0x26, 0xc4, 0xaf,
0x75, 0xea, 0xdb, 0x8b, 0xff, 0x9b, 0x9b, 0x50, 0x7e, 0xfe, 0x15, 0xab, 0x17, 0x2f, 0x96, 0x96,
0xbd, 0xaa, 0x87, 0xdd, 0x77, 0xa3, 0x77, 0xd3, 0x85, 0xf0, 0xe0, 0x58, 0xd5, 0xf6, 0x8c, 0xcd,
0xc4, 0x63, 0x52, 0x12, 0x48, 0x46, 0x0f, 0x93, 0x5a, 0xe3, 0xea, 0x24, 0x67, 0x73, 0x63, 0xa0,
0xdf, 0xdf, 0x3d, 0x67, 0xf6, 0xa9, 0xfc, 0xed, 0x08, 0xe3, 0x82, 0x57, 0x08, 0x35, 0x47, 0x68,
0x9c, 0x01, 0x40, 0x87, 0x8b, 0xbd, 0x0c, 0xb3, 0xf4, 0xe1, 0x72, 0xd7, 0x54, 0x62, 0xfd, 0x40,
0xed, 0x99, 0xa6, 0x7e, 0x2b, 0xe4, 0xb4, 0xc4, 0x62, 0x0d, 0x79, 0xae, 0x1b, 0xd7, 0xf4, 0x09,
0xb7, 0xe1, 0x7c, 0x44, 0x09, 0x9a, 0xda, 0xff, 0x52, 0x6a, 0x3c, 0xe1, 0xc8, 0xd7, 0xbd, 0xbb,
0xbe, 0x37, 0xfc, 0xd6, 0xd5, 0x4e, 0x3c, 0x40, 0x2a, 0x4b, 0x39, 0x1a, 0xbd, 0x2a, 0xcd, 0xc1,
0x18, 0x59, 0x40, 0x62, 0x78, 0xec, 0x63, 0x19, 0x72, 0xf0, 0xcf, 0xf8, 0x38, 0xfa, 0x42, 0x3a,
0xc8, 0x02, 0xec, 0x5b, 0xeb, 0x8d, 0xae, 0xf1, 0x45, 0xdd, 0x32, 0x98, 0x35, 0x3c, 0x9f, 0xa6,
0x3d, 0xce, 0x13, 0xce, 0x94, 0x38, 0x87, 0x00, 0x8d, 0x85, 0xc4, 0x70, 0x17, 0x26, 0x0e, 0xa6,
0x1e, 0x16, 0xcb, 0xbf, 0x52, 0xdf, 0x29, 0x63, 0xc4, 0xf6, 0x8c, 0x35, 0xba, 0xf2, 0xf9, 0x1f,
0xbf, 0x73, 0x1f, 0x91, 0x1b, 0x9e, 0x24, 0x5e, 0x63, 0x22, 0x82, 0x23, 0x05, 0x19, 0xb9, 0x71,
0x73, 0xdc, 0xcf, 0x05, 0x88, 0x94, 0x71, 0xdb, 0xdd, 0x48, 0x10, 0xd5, 0x55, 0xb3, 0x52, 0xc3,
0x1b, 0x01, 0x94, 0x13, 0x74, 0x94, 0x3a, 0x80, 0x2f, 0x39, 0xe2, 0x75, 0x0e, 0xf2, 0xc6, 0x18,
0xdc, 0x46, 0xfc, 0xf3, 0xea, 0x14, 0x80, 0xc1, 0xce, 0x24, 0xee, 0x72, 0xed, 0x94, 0xaf, 0xfb,
0xa9, 0xaa, 0x4a, 0xe0, 0xd4, 0x22, 0xc6, 0xf0, 0x57, 0x1d, 0x8e, 0xd2, 0x90, 0xc6, 0x0c, 0xd3,
0x9a, 0x53, 0xfb, 0xd6, 0xb7, 0xdd, 0x14, 0xd4, 0xbd, 0x41, 0xa7, 0x80, 0x7b, 0x23, 0xfe, 0x34,
0x56, 0x0d, 0x96, 0x46, 0x02, 0xfe, 0xfd, 0xb2, 0x00, 0x5f, 0x01, 0x9c, 0xa0, 0x32, 0x39, 0xd7,
0x90, 0xc2, 0x6c, 0xc7, 0x4e, 0x68, 0x88, 0x7d, 0x9f, 0x9b, 0xcf, 0xa7, 0xbe, 0xa0, 0xfc, 0x18,
0x7d, 0x07, 0x5b, 0xa9, 0xbe, 0x56, 0x1f, 0x67, 0x1a, 0x4a, 0x91, 0x9c, 0x04, 0x38, 0x53, 0x6b,
0x70, 0x68, 0x8f, 0xea, 0xf4, 0x34, 0x87, 0x7f, 0x6e, 0x82, 0xc3, 0xc1, 0xab, 0x40, 0xc4, 0x50,
0x13, 0x0e, 0x33, 0x5d, 0x67, 0x7d, 0x01, 0x1f, 0xdb, 0xc0, 0x7f, 0xed, 0x87, 0x7f, 0xbc, 0x0f,
0x75, 0xe0, 0xa5, 0xba, 0xc0, 0x84, 0x3d, 0x24, 0x04, 0xe0, 0xf1, 0x16, 0x41, 0x3b, 0x74, 0xd2,
0x52, 0xc5, 0xf8, 0x7c, 0x12, 0xfb, 0xe4, 0x37, 0x5b, 0xfb, 0x57, 0x11, 0xa1, 0x18, 0x00, 0x00,
};
using (var stream = new MemoryStream(bytes))
using (var gzip = new GZipStream(stream, CompressionMode.Decompress))
using (var reader = new BinaryReader(gzip))
{
while (true)
{
char ch = reader.ReadChar();
if (ch == '\0')
break;
int width = reader.ReadByte();
int height = reader.ReadByte();
bool[,] map = new bool[width, height];
for (int i = 0; i < width; i++)
for (int j = 0; j < height; j++)
map[i, j] = reader.ReadBoolean();
words_.Add(new CharInfo(ch, map));
}
}
}
public string Read(Bitmap bmp)
{
var result = string.Empty;
var width = bmp.Width;
var height = bmp.Height;
var table = ToTable(bmp);
var next = SearchNext(table, -1);
while (next < width - 7)
{
var matched = Match(table, next);
if (matched.Rate > 0.6)
{
result += matched.Char;
next = matched.X + 10;
}
else
{
next += 1;
}
}
return result;
}
private bool[,] ToTable(Bitmap bmp)
{
var table = new bool[bmp.Width, bmp.Height];
for (int i = 0; i < bmp.Width; i++)
for (int j = 0; j < bmp.Height; j++)
{
var color = bmp.GetPixel(i, j);
table[i, j] = (color.R + color.G + color.B < 500);
}
return table;
}
private int SearchNext(bool[,] table, int start)
{
var width = table.GetLength(0);
var height = table.GetLength(1);
for (start++; start < width; start++)
for (int j = 0; j < height; j++)
if (table[start, j])
return start;
return start;
}
private double FixedMatch(bool[,] source, bool[,] target, int x0, int y0)
{
double total = 0;
double count = 0;
int targetWidth = target.GetLength(0);
int targetHeight = target.GetLength(1);
int sourceWidth = source.GetLength(0);
int sourceHeight = source.GetLength(1);
int x, y;
for (int i = 0; i < targetWidth; i++)
{
x = i + x0;
if (x < 0 || x >= sourceWidth)
continue;
for (int j = 0; j < targetHeight; j++)
{
y = j + y0;
if (y < 0 || y >= sourceHeight)
continue;
if (target[i, j])
{
total++;
if (source[x, y])
count++;
else
count--;
}
else if (source[x, y])
count -= 0.55;
}
}
return count / total;
}
private MatchedChar ScopeMatch(bool[,] source, bool[,] target, int start)
{
int targetWidth = target.GetLength(0);
int targetHeight = target.GetLength(1);
int sourceWidth = source.GetLength(0);
int sourceHeight = source.GetLength(1);
double max = 0;
var matched = new MatchedChar();
for (int i = -2; i < 6; i++)
for (int j = -3; j < sourceHeight - targetHeight + 5; j++)
{
double rate = FixedMatch(source, target, i + start, j);
if (rate > max)
{
max = rate;
matched.X = i + start;
matched.Y = j;
matched.Rate = rate;
}
}
return matched;
}
private MatchedChar Match(bool[,] source, int start)
{
MatchedChar best = null;
foreach (var info in words_)
{
var matched = ScopeMatch(source, info.Table, start);
matched.Char = info.Char;
if (best == null || best.Rate < matched.Rate)
best = matched;
}
return best;
}
private class CharInfo
{
public char Char { get; private set; }
public bool[,] Table { get; private set; }
public CharInfo(char ch, bool[,] table)
{
Char = ch;
Table = table;
}
}
private class MatchedChar
{
public int X { get; set; }
public int Y { get; set; }
public char Char { get; set; }
public double Rate { get; set; }
}
}
}
應用辦法以下：
var cracker = new Cracker(); var result = cracker.Read(img);
願望本文所述對年夜家的C#法式設計有所贊助。
