AutoZone Method (IOcrPage)

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 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 page
      Using ocrPage As IOcrPage = ocrEngine.CreatePage(image, OcrImageSharingMode.AutoDispose)
         ' 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)

         ' 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)
      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(message As String, 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("  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 19\Bin\Common\OcrAdvantageRuntime"
End Class