AutoZone(OcrProgressCallback) 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 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.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()

         ' 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"
Public Const OcrAdvantageRuntimeDir As String = "C:\LEADTOOLS 18\Bin\Common\OcrAdvantageRuntime"
End Class