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OCR Tutorial - Working with Pages

Take the following steps to create and run a program that shows how to work with pages in an OCR document. Remember, the purpose of the tutorials is to provide you with a quick and easy way to generate an OCR program.

Start Visual Studio
Choose File->New->Project from the menu.
In the New Project dialog box, choose either "Visual C# Projects" or "VB Projects" in the Projects Type List, and choose "Windows Application" or "Windows Forms Application" depending on your Visual Studio Version from the Templates List.
Type the project name as "OcrTutorial" in the Project Name field, and then choose OK. If desired, type a new location for your project or select a directory using the Browse button, and then choose OK.
In the "Solution Explorer" window, right-click on the "References" folder, and select "Add Reference..." from the context menu. In the "Add Reference" dialog box, select the ".NET" tab and browse to LEADTOOLS For .NET "<LEADTOOLS_INSTALLDIR>\Bin\DotNet4\Win32" folder and select the following DLLs:
- Leadtools.dll
- Leadtools.Codecs.dll
- Leadtools.Forms.Common.dll
- Leadtools.Document.Writer.dll
- Leadtools.Ocr.dll
- Leadtools.Ocr.LEADEngine.dll
- Leadtools.Codecs.Bmp.dll
- Leadtools.Codecs.Cmp.dll
- Leadtools.Codecs.Tif.dll
- Leadtools.Codecs.Fax.dll
Note: The Leadtools.Codecs.*.dll references added are for the BMP, JPG, CMP, TIF and FAX image formats. Add any additional file format codec DLL if required in your application.

Drag and drop five buttons in Form1. Leave all the buttons names as the default "button1, button2 ...", then change the Text property of each button to the following:

Button	Text
button1	Startup
button2	Add Page
button3	Remove Pages
button4	Flip Page
button5	Shutdown

Switch to Form1 code view (Right-click Form1 in the solution explorer then select View Code) and add the following lines at the beginning of the file after any using or Imports section if there are any:

      using Leadtools; 
      using Leadtools.Codecs; 
      using Leadtools.Forms.Common; 
      using Leadtools.Document.Writer; 
      using Leadtools.Ocr; 
      using Leadtools.ImageProcessing;

      Imports Leadtools 
      Imports Leadtools.Codecs 
      Imports Leadtools.Forms.Common 
      Imports Leadtools.Document.Writer 
      Imports Leadtools.Ocr 
      Imports Leadtools.ImageProcessing

Add the following private variables to the Form1 class:

      private IOcrEngine _ocrEngine; 
      private IOcrDocument _ocrDocument;

      Private _ocrEngine As IOcrEngine 
      Private _ocrDocument As IOcrDocument

Add the following code for the button1 (Startup) Click handler:

      private void button1_Click(object sender, EventArgs e) 
      { 
         string MY_LICENSE_FILE = @"C:\LEADTOOLS 20\Support\Common\License\leadtools.lic"; 
         string MY_DEVELOPER_KEY = System.IO.File.ReadAllText(@"C:\LEADTOOLS 20\Support\Common\License\leadtools.lic.key"); 
         RasterSupport.SetLicense(MY_LICENSE_FILE, MY_DEVELOPER_KEY); 
 
         // Initialize the OCR engine 
         _ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD, false); 
         // Start it up 
         _ocrEngine.Startup(null, null, null, @"C:\LEADTOOLS 20\Bin\Common\OcrLEADRuntime"); 
         // Create the document 
          _ocrDocument = _ocrEngine.DocumentManager.CreateDocument(); 
         MessageBox.Show("OCR engine has been started successfully and document created"); 
      }

      Private Sub button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button1.Click 
        ' Requires a license file that unlocks 1D barcode read functionality. 
         Dim MY_LICENSE_FILE As String = "C:\LEADTOOLS 20\Support\Common\License\leadtools.lic" 
         Dim MY_DEVELOPER_KEY As String = System.IO.File.ReadAllText("C:\LEADTOOLS 20\Support\Common\License\leadtools.lic.key") 
         RasterSupport.SetLicense(MY_LICENSE_FILE, MY_DEVELOPER_KEY) 
 
         ' Initialize the OCR engine 
         _ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD, False) 
         ' Start it up 
         _ocrEngine.Startup(Nothing, Nothing, Nothing, "C:\LEADTOOLS 20\Bin\Common\OcrLEADRuntime") 
         ' Create the document 
          _ocrDocument = _ocrEngine.DocumentManager.CreateDocument() 
         MessageBox.Show("OCR engine has been started successfully and document created") 
      End Sub

Add the following code for the button2 (Add Page) Click handler:

      private void button2_Click(object sender, EventArgs e) 
      { 
         // Browse to an existing document file on disk, for example @"C:\Users\Public\Documents\LEADTOOLS Images\Ocr1.tif"; 
         string fileName = null; 
         using (OpenFileDialog dlg = new OpenFileDialog()) 
         { 
            if (dlg.ShowDialog(this) == DialogResult.OK) 
               fileName = dlg.FileName; 
         } 
                 
         if (fileName == null) 
            return; 
                 
         // Add the first page from the file to the OCR document 
         IOcrPage page = _ocrDocument.Pages.AddPage(fileName, null); 
         int pageCount = _ocrDocument.Pages.Count; 
         // Show some information about this page 
         string message = string.Format( 
            "Total pages is {0}\nLast page added size = {1} by {2}\nResolution = {3} by {4}\nBits per pixel = {5}", 
            pageCount, 
            page.Width, page.Height, 
            page.DpiX, page.DpiY, 
            page.BitsPerPixel); 
         MessageBox.Show(message); 
      }

      Private Sub button2_Click(sender As Object, e As EventArgs) 
         ' Browse to an existing document file on disk, for example @"C:\Users\Public\Documents\LEADTOOLS Images\Ocr1.tif"; 
         Dim fileName As String = Nothing 
         Using dlg As New OpenFileDialog() 
            If dlg.ShowDialog(Me) = DialogResult.OK Then 
               fileName = dlg.FileName 
            End If 
         End Using 
                 
         If IsNothing(fileName) Then Return 
                 
         ' Add the first page from the file to the OCR document 
         Dim page As IOcrPage = _ocrDocument.Pages.AddPage(fileName, Nothing) 
         Dim pageCount As Integer = _ocrDocument.Pages.Count 
         ' Show some information about this page 
         Dim message As String = String.Format( _ 
            "Total pages is {0}\nLast page added size = {1} by {2}\nResolution = {3} by {4}\nBits per pixel = {5}", _ 
            pageCount, _ 
            page.Width, page.Height, _ 
            page.DpiX, page.DpiY, _ 
            page.BitsPerPixel) 
         MessageBox.Show(message) 
      End Sub

Add the following code for the button3 (Remove Pages) Click handler:

      private void button3_Click(object sender, EventArgs e) 
      { 
         // Remove all added pages from the OCR document 
         _ocrDocument.Pages.Clear(); 
         MessageBox.Show("All the pages have been removed"); 
      }

      Private Sub button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button3.Click 
         ' Remove all added pages from the OCR document 
         _ocrDocument.Pages.Clear() 
         MessageBox.Show("All the pages have been removed") 
      End Sub

Add the following code for the button4 (Flip Page) Click handler:

      private void button4_Click(object sender, EventArgs e) 
      { 
         // Get the last page added to the OCR document 
         if (_ocrDocument.Pages.Count < 1) 
            return; 
                 
         IOcrPage page = _ocrDocument.Pages[_ocrDocument.Pages.Count - 1]; 
         // Get a RasterImage that represents this page 
         using (RasterImage image = page.GetRasterImage()) 
         { 
            // Flip this image vertically 
            FlipCommand cmd = new FlipCommand(false); 
            cmd.Run(image); 
            // The RasterImage is a copy of the page, so update it 
            page.SetRasterImage(image); 
            MessageBox.Show("Last page has been flipped"); 
         } 
      }

      Private Sub button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button4.Click 
         ' Get the last page added to the OCR document 
         If (_ocrDocument.Pages.Count < 1) Then 
            Return 
         End If 
         Dim page As IOcrPage = _ocrDocument.Pages(_ocrDocument.Pages.Count - 1) 
         ' Get a RasterImage that represents this page 
         Using image As RasterImage = page.GetRasterImage() 
            ' Flip this image vertically 
            Dim cmd As New FlipCommand(False) 
            cmd.Run(image) 
            ' The RasterImage is a copy of the page, so update it 
            page.SetRasterImage(image) 
            MessageBox.Show("Last page has been flipped") 
         End Using 
      End Sub

Add the following code for the button5 (Shutdown) Click handler:

      private void button5_Click(object sender, EventArgs e) 
      { 
         // Destroy the document 
         _ocrDocument.Dispose(); 
         // Destroy the engine (will also shut it down) 
         _ocrEngine.Dispose(); 
         MessageBox.Show("OCR engine and document have been destroyed"); 
      }

      Private Sub button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button5.Click 
         ' Destroy the document 
         _ocrDocument.Dispose() 
         ' Destroy the engine (will also shut it down) 
         _ocrEngine.Dispose() 
         MessageBox.Show("OCR engine and document have been destroyed") 
      End Sub