使用AForge.NET框架和Tesseract识别验证码

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:

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