GetRecognizedCharacters Method

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.Forms.Ocr
Imports Leadtools.Forms
Imports Leadtools.Forms.DocumentWriters
Imports Leadtools.WinForms
Imports Leadtools.ImageProcessing.Core
Imports Leadtools.Drawing

Public Sub RecognizedCharactersExample()
   ' Create an image with some text in it
   Dim image As New RasterImage(RasterMemoryFlags.Conventional, 320, 200, 24, RasterByteOrder.Bgr, RasterViewPerspective.TopLeft, Nothing, IntPtr.Zero, 0)
   Dim imageRect As New Rectangle(0, 0, image.ImageWidth, image.ImageHeight)
   Dim hdc As IntPtr = RasterImagePainter.CreateLeadDC(image)
   Using g As Graphics = Graphics.FromHdc(hdc)
      g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality
      g.FillRectangle(Brushes.White, imageRect)

      Using f As New Font("Arial", 20, FontStyle.Regular)
         g.DrawString("Normal line", f, Brushes.Black, 0, 0)
      End Using

      Using f As New Font("Arial", 20, FontStyle.Bold Or FontStyle.Italic)
         g.DrawString("Bold and italic line", f, Brushes.Black, 0, 40)
      End Using

      Using f As New Font("Courier New", 20, FontStyle.Regular)
         g.DrawString("Monospaced line", f, Brushes.Black, 0, 80)
      End Using
   End Using

   RasterImagePainter.DeleteLeadDC(hdc)

   Dim textFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "MyImageWithTest.txt")
   Dim pdfFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "MyImageWithTest.pdf")

   ' Create an instance of the engine
   Using ocrEngine As IOcrEngine = OcrEngineManager.CreateEngine(OcrEngineType.Advantage, False)
      ' Start the engine using default parameters
      ocrEngine.Startup(Nothing, Nothing, Nothing, LEAD_VARS.OcrAdvantageRuntimeDir)

      ' Create an OCR document
      Using ocrDocument As IOcrDocument = ocrEngine.DocumentManager.CreateDocument()

         ' Add this image to the document
         Dim ocrPage As IOcrPage = ocrDocument.Pages.AddPage(image, Nothing)
         image.Dispose()

         ' Recognize this page
         ocrPage.Recognize(Nothing)

         ' Dump the characters into a text file
         Using writer As StreamWriter = File.CreateText(textFileName)
            Dim ocrPageCharacters As IOcrPageCharacters = ocrPage.GetRecognizedCharacters()
            For Each ocrZoneCharacters As IOcrZoneCharacters In ocrPageCharacters
               ' Show the words found in this zone. Get the word boundaries in inches
               Dim words As ICollection(Of OcrWord) = ocrZoneCharacters.GetWords(ocrPage.DpiX, ocrPage.DpiY, LogicalUnit.Inch)
               Console.WriteLine("Words:")
               For Each word As OcrWord In words
                  Console.WriteLine("Word: {0}, at {1}, characters index from {2} to {3}", word.Value, word.Bounds, word.FirstCharacterIndex, word.LastCharacterIndex)
               Next

               Dim nextCharacterIsNewWord As Boolean = True

               For i As Integer = 0 To ocrZoneCharacters.Count - 1
                  Dim ocrCharacter As OcrCharacter = ocrZoneCharacters(i)

                  ' Capitalize the first letter if this is a new word
                  If (nextCharacterIsNewWord) Then
                     ocrCharacter.Code = Char.ToUpper(ocrCharacter.Code)
                  End If

                  writer.WriteLine("Code: {0}, Confidence: {1}, WordIsCertain: {2}, Bounds: {3}, Position: {4}, FontSize: {5}, FontStyle: {6}", _
                     ocrCharacter.Code, _
                     ocrCharacter.Confidence, _
                     ocrCharacter.WordIsCertain, _
                     ocrCharacter.Bounds, _
                     ocrCharacter.Position, _
                     ocrCharacter.FontSize, _
                     ocrCharacter.FontStyle)

                  ' If the charcater is italic, make it underline
                  If ((ocrCharacter.FontStyle And OcrCharacterFontStyle.Italic) = OcrCharacterFontStyle.Italic) Then
                     ocrCharacter.FontStyle = ocrCharacter.FontStyle And (Not OcrCharacterFontStyle.Italic)
                     ocrCharacter.FontStyle = ocrCharacter.FontStyle Or OcrCharacterFontStyle.Underline
                  End If

                  ' Check if next character is the start of a new word
                  If ((ocrCharacter.Position And OcrCharacterPosition.EndOfWord) = OcrCharacterPosition.EndOfWord OrElse _
                        (ocrCharacter.Position And OcrCharacterPosition.EndOfLine) = OcrCharacterPosition.EndOfLine) Then
                     nextCharacterIsNewWord = True
                  Else
                     nextCharacterIsNewWord = False
                  End If

                  ocrZoneCharacters(i) = ocrCharacter
               Next
            Next

            ' Replace the characters with the modified one before we save
            ocrPage.SetRecognizedCharacters(ocrPageCharacters)
         End Using

         ' Show the recognition results
         ' Set the PDF options to save as PDF/A text only
         Dim pdfOptions As PdfDocumentOptions = DirectCast(ocrEngine.DocumentWriterInstance.GetOptions(DocumentFormat.Pdf), PdfDocumentOptions)
         pdfOptions.DocumentType = PdfDocumentType.PdfA
         pdfOptions.ImageOverText = False
         ocrEngine.DocumentWriterInstance.SetOptions(DocumentFormat.Pdf, pdfOptions)

         ocrDocument.Save(pdfFileName, DocumentFormat.Pdf, Nothing)

         ' Open and check the result file, it should contain the following text
         ' "Normal Line"
         ' "Bold And Italic Line"
         ' "Monospaced Line"
         ' With the second line bold and underlined now
      End Using

      ' Shutdown the engine
      ' Note: calling Dispose will also automatically shutdown the engine if it has been started
      ocrEngine.Shutdown()
   End Using
End Sub

Public NotInheritable Class LEAD_VARS
Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
Public Const OcrAdvantageRuntimeDir As String = "C:\LEADTOOLS 18\Bin\Common\OcrAdvantageRuntime"
End Class