使用AForge.NET框架和Tesseract识别验证码

水深无声 2021-06-26 16:06 540阅读 0赞

using AForge.Imaging.Filters;
    using System;
    using System.ComponentModel;
    using System.Drawing;
    using System.Windows.Forms;
    using Tesseract;
    
    namespace RecogCaptcha
    { 
        public partial class Form1 : Form
        { 
            public Form1()
            { 
                InitializeComponent();
            }
    
            private void openImageButton_Click(object sender, EventArgs e)
            { 
                openFileDialog.ShowDialog();
            }
    
            private void openFileDialog_FileOk(object sender, CancelEventArgs e)
            { 
                Bitmap image = new Bitmap(openFileDialog.FileName);
                if (image != null)
                { 
                    System.IO.FileInfo fi = new System.IO.FileInfo(openFileDialog.FileName);
                    resultLabel.Text = reconhecerCaptcha(image);
                }
                image.Dispose();
            }
    
            private string reconhecerCaptcha(Image img)
            { 
                Bitmap imagem = new Bitmap(img);
                imagem = imagem.Clone(new Rectangle(0, 0, img.Width, img.Height), System.Drawing.Imaging.PixelFormat.Format24bppRgb);
                Erosion erosion = new Erosion();
                Dilatation dilatation = new Dilatation();
                Invert inverter = new Invert();
                ColorFiltering cor = new ColorFiltering();
                cor.Blue = new AForge.IntRange(200, 255);
                cor.Red = new AForge.IntRange(200, 255);
                cor.Green = new AForge.IntRange(200, 255);
                Opening open = new Opening();
                BlobsFiltering bc = new BlobsFiltering();
                Closing close = new Closing();
                GaussianSharpen gs = new GaussianSharpen();
                ContrastCorrection cc = new ContrastCorrection();
                bc.MinHeight = 10;
                FiltersSequence seq = new FiltersSequence(gs, inverter, open, inverter, bc, inverter, open, cc, cor, bc, inverter);
                pictureBox.Image = seq.Apply(imagem);
                string reconhecido = OCR((Bitmap)pictureBox.Image);
                return reconhecido;
            }
    
            private string OCR(Bitmap b)
            { 
                string res = "";
                using (var engine = new TesseractEngine(@"tessdata", "eng", EngineMode.Default))
                { 
                    engine.SetVariable("tessedit_char_whitelist", "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ");
                    engine.SetVariable("tessedit_unrej_any_wd", true);
    
                    using (var page = engine.Process(b, PageSegMode.SingleLine))
                        res = page.GetText();
                }
                return res;
            }
        }
    }

## 结果如图: ##

![在这里插入图片描述][2020110823094586.png]  
![在这里插入图片描述][20201108230959536.png]  
[下载][Link 1]

[2020110823094586.png]: /images/20210626/46742b9bb9764c04aad32b4d8d6a1aa0.png
[20201108230959536.png]: /images/20210626/4e0c28ee76de4bdfa73e890b5e4503c2.png
[Link 1]: https://download.csdn.net/download/WuLex/13097697