GetRecognizedCharacters Method

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

<TestMethod>
Public Sub RecognizedCharactersExample()
   ' Create an image with some text in it
   Dim image As New RasterImage(RasterMemoryFlags.Conventional, _
                                 640, 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)
         g.DrawString("Bold, italic and underline", 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 page
      Dim ocrPage As IOcrPage = ocrEngine.CreatePage(image, OcrImageSharingMode.AutoDispose)

      ' 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 bold, make it underline
               If (ocrCharacter.FontStyle And OcrCharacterFontStyle.Bold) = OcrCharacterFontStyle.Bold Then
                  ocrCharacter.FontStyle = ocrCharacter.FontStyle Or 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

      ' Create an OCR document so we can save the results
      Using ocrDocument As IOcrDocument = ocrEngine.DocumentManager.CreateDocument(Nothing, OcrCreateDocumentOptions.AutoDeleteFile)
         ' Add the page and dispose it
         ocrDocument.Pages.Add(ocrPage)
         ocrPage.Dispose()

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


         ' 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
         ocrDocument.Save(pdfFileName, DocumentFormat.Pdf, Nothing)
      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 19\Bin\Common\OcrAdvantageRuntime"
End Class