TUTORIAL DECAPTCHA WITH AFORGE.NET WINFORM

'https://laptrinhvb.net/bai-viet/chuyen-de-csharp/---Csharp----Huong-dan-DeCaptcha-su-dung-thu-vien-Aforge-NET/868d43071f4f2649.html

Imports AForge.Imaging.Filters
Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Linq
Imports System.Text
Imports System.Threading.Tasks
Imports System.Windows.Forms
Imports Tesseract

Namespace DeCaptcha
    Public Partial Class Form1
        Inherits Form

        Public Sub New()
            InitializeComponent()
        End Sub

        Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
        End Sub

        Private Function reconhecerCaptcha(ByVal img As Image) As String
            Dim imagem As Bitmap = New Bitmap(img)
            imagem = imagem.Clone(New Rectangle(0, 0, img.Width, img.Height), System.Drawing.Imaging.PixelFormat.Format24bppRgb)
            Dim erosion As Erosion = New Erosion()
            Dim dilatation As Dilatation = New Dilatation()
            Dim inverter As Invert = New Invert()
            Dim cor As ColorFiltering = New ColorFiltering()
            cor.Blue = New AForge.IntRange(200, 255)
            cor.Red = New AForge.IntRange(200, 255)
            cor.Green = New AForge.IntRange(200, 255)
            Dim open As Opening = New Opening()
            Dim bc As BlobsFiltering = New BlobsFiltering()
            Dim close As Closing = New Closing()
            Dim gs As GaussianSharpen = New GaussianSharpen()
            Dim cc As ContrastCorrection = New ContrastCorrection()
            bc.MinHeight = 10
            Dim seq As FiltersSequence = New FiltersSequence(gs, inverter, open, inverter, bc, inverter, open, cc, cor, bc, inverter)
            pic_decaptcha.Image = seq.Apply(imagem)
            Dim reconhecido As String = OCR(CType(pic_decaptcha.Image, Bitmap))
            Return reconhecido
        End Function

        Private Function OCR(ByVal b As Bitmap) As String
            Dim res As String = ""

            Using engine = New TesseractEngine("tessdata", "eng", EngineMode.[Default])
                engine.SetVariable("tessedit_char_whitelist", "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ")
                engine.SetVariable("tessedit_unrej_any_wd", True)

                Using page = engine.Process(b, PageSegMode.SingleLine)
                    res = page.GetText()
                End Using
            End Using

            Return res
        End Function

        Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs)
            If openFileDialog.ShowDialog() = DialogResult.OK Then
                pic_orgin.LoadAsync(openFileDialog.FileName)
            End If
        End Sub

        Private Sub btn_decaptcha_Click(ByVal sender As Object, ByVal e As EventArgs)
            resultLabel.Text = reconhecerCaptcha(pic_orgin.Image)
        End Sub
    End Class
End Namespace