AutoZone(OcrProgressCallback) Method

'Declaration
 
Overloads Sub AutoZone( _
   ByVal callback As OcrProgressCallback _
) 

Public Sub OcrAutoZoneExample()
      ' 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("Courier New", 20, FontStyle.Regular)
            g.DrawString("Monospaced line", f, Brushes.Black, 0, 80)
         End Using
      End Using

      RasterImagePainter.DeleteLeadDC(hdc)

      Dim zonesFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "MyZones.xml")

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

         ' 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()

            ' Show the zones, there should be no zones yet
            ShowZones("Right after the page was created", ocrPage)

            ' Perform default AutoZoning on the page
            ocrPage.AutoZone(Nothing)

            ' Show the zones, there should be two zones, one for each line
            ShowZones("AutoZone with default parameters", ocrPage)

            ' Upda the fill methods of the zones
            ocrPage.UpdateFillMethod()

            ' Show the zones after the fill method has been updated
            ShowZones("After updating the fill methods", ocrPage)

            ' Update the first zone manually
            Dim ocrZone As OcrZone = ocrPage.Zones(0)
            ocrZone.ZoneType = OcrZoneType.Text
            ocrPage.Zones(0) = ocrZone

            ' Show the zones
            ShowZones("After updating the type of the first zone", ocrPage)

            ' Save the zones to a file and then clear them
            ocrPage.SaveZones(zonesFileName)
            ocrPage.Zones.Clear()

            ' Show the zones, there should be no zones since we just cleared them
            ShowZones("After calling save and clear", ocrPage)

            ' Re-load the zones
            ocrPage.LoadZones(zonesFileName)
            ShowZones("After re-loading the zones", ocrPage)

            ' To do manual auto zoning, it is helpful to first get the fill method of the page
            Dim fillMethod As OcrZoneFillMethod = ocrPage.DetectFillMethod()
            Console.WriteLine("Fill method detected: {0}", fillMethod)

            ' Clear the zones and do auto zone with specific options
            ocrPage.AutoZone(OcrZoneParser.Default, fillMethod, LogicalUnit.Inch, Nothing)
            ShowZones("After AutoZone with specific options, units should be in inches", ocrPage)
         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

   Private Sub ShowZones(ByVal message As String, ByVal ocrPage As IOcrPage)
      Console.WriteLine("Zones after {0}:", message)
      For Each ocrZone As OcrZone In ocrPage.Zones
         Dim index As Integer = ocrPage.Zones.IndexOf(ocrZone)
         Console.WriteLine("Zone index: {0}", index)
         Console.WriteLine("  Id                  {0}", ocrZone.Id)
         Console.WriteLine("  Bounds              {0}", ocrZone.Bounds)
         Console.WriteLine("  ZoneType            {0}", ocrZone.ZoneType)
         Console.WriteLine("  FillMethod:         {0}", ocrZone.FillMethod)
         Console.WriteLine("  RecognitionModule:  {0}", ocrZone.RecognitionModule)
         Console.WriteLine("  CharacterFilters:   {0}", ocrZone.CharacterFilters)
         Console.WriteLine("----------------------------------")
      Next

      Console.WriteLine("Hit enter to continue")
      Console.ReadLine()
   End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class