C# 实现验证码识别

【实例截图】

【核心代码】

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

using System.IO;
using System.IO.Compression;


namespace AuctionLicenseSH
{ 
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //this.buttonOcrTip.PerformClick();
            this.buttonOcrTarget.PerformClick();
        }

        private void buttonOcrTip_Click(object sender, EventArgs e)
        {
            Cracker cracker;

            int indexCount = 0;
            int indexSuccess = 0;
            int indexFail = 0;
            string outMessage = "";
            DirectoryInfo dir;

            //识别语义
            indexCount = 0;
            indexSuccess = 0;
            indexFail = 0;
            cracker = new Cracker(".//template_tip");
            cracker.OcrRate = 0.8;
            dir = new DirectoryInfo(".//tip");
            foreach (FileInfo f in dir.GetFiles())
            {
                DateTime start = DateTime.Now;
                string fileFullPath = f.FullName;
                Bitmap img = new Bitmap(fileFullPath);
                var result = cracker.Read(img);

                string fileName = f.FullName.Substring(f.FullName.LastIndexOf('\\')   1);
                string fileNameWithoutPostFix = fileName.Substring(0, fileName.LastIndexOf('.'));   //去除后缀
                string SuccessOrFail;
                if (result.Length >0 && result.Substring(0, 1) == fileNameWithoutPostFix.Substring(0, 1))    //只需比第一个字符
                {
                    indexSuccess  ;
                    SuccessOrFail = "成功"   indexSuccess.ToString();
                }
                else
                {
                    indexFail  ;
                    SuccessOrFail = "失败"   indexFail.ToString();
                }

                DateTime stop = DateTime.Now;
                TimeSpan time = stop.Subtract(start);
                int iEclapse = time.Seconds * 1000   time.Milliseconds;

                indexCount  ;
                outMessage  = indexCount.ToString()   ","   SuccessOrFail   ","   fileName   ","   result.ToString()
                      ","   iEclapse.ToString()   "毫秒"   Environment.NewLine;

                img.Dispose();
            }
            this.textBox1.Text  = outMessage;
        }

        private void buttonOcrTarget_Click(object sender, EventArgs e)
        {
            Cracker cracker;
            cracker = new Cracker(".//template_target", Cracker.enumOcrType.OcrTarget);
            cracker.OcrRate = 0.5;

            int indexCount = 0;
            int indexSuccess = 0;
            int indexFail = 0;
            string outMessage = "";
            DirectoryInfo dir;

            //识别数字
            dir = new DirectoryInfo(".//target");
            foreach (FileInfo f in dir.GetFiles())
            {
                DateTime start = DateTime.Now;
                string fileFullPath = f.FullName;
                Bitmap img = new Bitmap(fileFullPath);
                var result = cracker.Read(img);

                string fileName = f.FullName.Substring(f.FullName.LastIndexOf('\\')   1);
                string fileNameWithoutPostFix = fileName.Substring(0, fileName.LastIndexOf('.'));   //去除后缀
                string SuccessOrFail;
                if (result == fileNameWithoutPostFix)
                {
                    indexSuccess  ;
                    SuccessOrFail = "成功"   indexSuccess.ToString();
                }
                else
                {
                    indexFail  ;
                    SuccessOrFail = "失败"   indexFail.ToString();
                }

                DateTime stop = DateTime.Now;
                TimeSpan time = stop.Subtract(start);
                int iEclapse = time.Seconds * 1000   time.Milliseconds;

                indexCount  ;
                outMessage  = indexCount.ToString()   ","   SuccessOrFail   ","   fileName   ","   result.ToString()
                      ","   iEclapse.ToString()   "毫秒"   Environment.NewLine;

                img.Dispose();
            }
            this.textBox1.Text  = outMessage;
            
        }
    }

    public class Cracker
    {    
        public enum enumOcrType
        {
            /// <summary>
            /// 识别提示
            /// </summary>
            OcrTip,
            /// <summary>
            /// 识别数字
            /// </summary>
            OcrTarget,
        }

        public 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; }
        }

        public List<CharInfo> words_ = new List<CharInfo>();

        /// <summary>
        /// 识别率
        /// </summary>
        private double _OcrRate;
        public double OcrRate
        {
            get { return _OcrRate; }
            set { _OcrRate = value; }
        }

        private enumOcrType _OcrType;
        public AuctionLicenseSH.Cracker.enumOcrType OcrType
        {
            get { return _OcrType; }
            set { _OcrType = value; }
        }

        public Cracker(string templatePath, enumOcrType OcrType = enumOcrType.OcrTip)
        {
            _OcrType = OcrType;
            _OcrRate = 0.5;
            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));
                }
            }

            ReadTemplate(templatePath);
        }

        /// <summary>
        /// 读取字符的模板
        /// </summary>
        /// <param name="fileName"></param>
        public void ReadTemplate(string folderPath)
        {
            DirectoryInfo dir = new DirectoryInfo(folderPath);
            foreach (FileInfo f in dir.GetFiles())
            {
                Bitmap img = new Bitmap(f.FullName);
                var table = ToTable(img);
                int width = img.Width;
                int height = img.Height;

                string fileName = f.FullName.Substring(f.FullName.LastIndexOf('\\')   1);
                char ch = fileName.ToCharArray()[0];

                words_.Add(new CharInfo(ch, table));

                img.Dispose();
            }
            
        }

        

        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);
                //完成了一次最佳匹配，可以把匹配位置向右推进一大步，若找不到合适的最佳匹配就向右推进一小步。
                if (matched.Rate >= _OcrRate)
                {
                    result  = matched.Char;
                    next = matched.X   14;

                    //目前，提示语句只需识别第一个字符
                    if (_OcrType == enumOcrType.OcrTip)
                    {
                        return result;
                    }
                }
                else
                {
                    next  = 1;
                }
            }

            return result;
        }

        /// <summary>
        /// Bitmap做2值化
        /// </summary>
        /// <param name="bmp"></param>
        /// <returns></returns>
        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 < 600);
                }
            }
            return table;
        }

        /// <summary>
        /// 逐列扫描，找到有值的第一列
        /// </summary>
        /// <param name="table"></param>
        /// <param name="start"></param>
        /// <returns></returns>
        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;
        }

        /// <summary>
        /// 遍历匹配字库，取匹配率最高的
        /// </summary>
        /// <param name="source"></param>
        /// <param name="start"></param>
        /// <returns></returns>
        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 || matched.Rate > best.Rate)
                    best = matched;
            }
            return best;
        }

        /// <summary>
        /// 扫描缓冲范围内的所有点，作为起始点匹配点，取匹配率最高的
        /// </summary>
        /// <param name="source"></param>
        /// <param name="target"></param>
        /// <param name="start"></param>
        /// <returns></returns>
        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;
        }

        /// <summary>
        /// 计算，以x0、y0作为原点，匹配的比率
        /// </summary>
        /// <param name="source"></param>
        /// <param name="target"></param>
        /// <param name="x0"></param>
        /// <param name="y0"></param>
        /// <returns></returns>
        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;

            //比对每一个像素
            for (int i = 0; i < targetWidth; i  )
            {
                x = i   x0;
                if (x < 0 || x >= sourceWidth)
                {
                    continue;   //超出范围，则退出
                }
                for (int j = 0; j < targetHeight; j  )
                {
                    y = j   y0;
                    if (y < 0 || y >= sourceHeight)
                    {
                        continue;   //超出范围，则退出
                    }

                    //目标像素有值时，直接比对
                    if (target[i, j])
                    {
                        total  ;    //总值
                        if (source[x, y])
                        {
                            count  ;    //比对上了，加1分
                        }
                        else
                        {
                            count--;    //减1分
                        }
                    }
                    //目标像素无值时，如果源像素有值，也要减分，但只减半
                    else if (source[x, y])
                    {
                        count -= 0.55;
                    }
                }
            }

            return count / total;
        }

        /// <summary>
        /// 测试压缩解压缩
        /// </summary>
        public void testCompressDecompress()
        {
            CharInfo charinfo = words_[0];
            char ch = charinfo.Char;
            int width = 12;
            int height = 14;
            bool[,] map = charinfo.Table;
            //测试压缩出第一个字符的模板
            byte[] buffer = new byte[171];
            buffer[0] = (byte)ch;
            buffer[1] = (byte)width;
            buffer[2] = (byte)height;

            int index = 2;
            for (int i = 0; i < width; i  )
            {
                for (int j = 0; j < height; j  )
                {
                    index  ;
                    if (map[i, j])
                    {
                        buffer[index] = 0x01;
                    }
                    else
                    {
                        buffer[index] = 0x00;
                    }
                }
            }

            //using (var stream2 = new MemoryStream(buffer))
            //using (var gzip2 = new GZipStream(stream2, CompressionMode.Compress))                        

            //压缩
            FileStream fstream = new FileStream("compress.txt", FileMode.Create, FileAccess.Write);
            GZipStream gstream = new GZipStream(fstream, CompressionMode.Compress);
            BinaryWriter swriter = new BinaryWriter(gstream);
            swriter.Write(buffer);

            swriter.Close();
            gstream.Close();
            fstream.Close();

            //解压
            FileStream fstream2 = new FileStream("compress.txt", FileMode.Open, FileAccess.Read);
            GZipStream gstream2 = new GZipStream(fstream2, CompressionMode.Decompress);
            BinaryReader reader2 = new BinaryReader(gstream2);

            byte[] bufferDecompress = new byte[171];
            for (int i = 0; i < 171; i  )
            {

                bufferDecompress[i] = (byte)reader2.ReadByte();
            }

            reader2.Close();
            gstream2.Close();
            fstream2.Close();
        }
    }
}