Writing and Reading Pages

Take the following steps to start a project and to add some code that writes and reads pages to/from an image file:

Start Visual Studio .NET.
Choose File->New->Project… from the menu.
In the New Project dialog box, choose either "Visual C# Projects" or "Visual Basic Projects" in the Projects Type List, and choose "Windows Application " in the Templates List.
Type the project name as " Writing and Reading Pages" 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 "\LEAD Technologies\LEADTOOLS 15\Bin\DotNet\Win32 " folder and select the following DLLs:
- Leadtools.dll
- Leadtools.Codecs.dll
- Leadtools.WinForms.dll
Press the Select button and then press the OK button to add the above DLLs to the application.
Make sure Form1 is in design view. Go to the toolbox (View->Toolbox) and Drag and drop an instance of RasterImageViewer to the form. If you do not have RasterImageViewer in your toolbox, select Tools->Add Remove Toolbox Items from the menu. Click Browse and then select Leadtools.WinForms.DLL from "C:\Program Files\LEAD Technologies\LEADTOOLS 15\Bin\DotNet\Win32" and then click Open and then click OK.
From the toolbox (View->Toolbox ), add 4 Button controls as follows:

Name Text

Button1 First

Button2 Previous

Button3 Next

Button4 Last

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:

[Visual Basic]

 
Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.WinForms

[C#]

 
using Leadtools;
using Leadtools.Codecs;
using Leadtools.WinForms;

Add an event handler to the Form1 Load event and add the following code:

[Visual Basic]


             
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
   ' Intitialize a new RasterCodecs object.
   RasterCodecs.Startup()
   Dim codecs As New RasterCodecs()

   ' Load OCR1 to OCR4 and add them all to one image
   Dim pageFileName() As String = _
   { _
      "C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Ocr1.tif", _
      "C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Ocr2.tif", _
      "C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Ocr3.tif", _
      "C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Ocr4.tif" _
   }

   ' load all the files in pageFileName as pages into one image
   Dim image As RasterImage = Nothing

   For i As Integer = 0 To pageFileName.Length - 1
      ' load the page image
      Dim page As RasterImage = codecs.Load(pageFileName(i))
      If (i = 0) Then
         ' first image, just save it into our variable
         image = page
      Else
         ' add this page into our image
         image.AddPage(page)

         ' we do not need this page anymore
         page.Dispose()
      End If
   Next

   ' we can now use this image in our viewer.  But let us try saving into a multi-page file then reloading it

   Dim outputFileName As String = "C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Ocr_All.tif"

   ' we can now just put "image" into the viewer, but lets save it as multi-page tiff and reload it
   codecs.Save(image, outputFileName, RasterImageFormat.Tif, 1, 1, 4, 1, CodecsSavePageMode.Overwrite)
   image.Dispose()

   ' load this file into a new image and put in the viewer.

   ' we know we have four pages, but let us use the GetInformation pages to get the number of pages
   Dim info As CodecsImageInfo = codecs.GetInformation(outputFileName, True)
   image = codecs.Load(outputFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, info.TotalPages)

   ' setup the viewer into Fit mode
   RasterImageViewer1.SizeMode = RasterPaintSizeMode.Fit

   ' view this image
   RasterImageViewer1.Image = image
   UpdateCaption()

   RasterCodecs.Shutdown()
End Sub
   
Private Sub UpdateCaption()
   Text = String.Format("Page {0} of {1}", RasterImageViewer1.Image.Page, RasterImageViewer1.Image.PageCount)
End Sub

[C#]

 
private void Form1_Load(object sender, System.EventArgs e)
{
   // Intitialize a new RasterCodecs object.
   RasterCodecs.Startup();
   RasterCodecs codecs = new RasterCodecs();

   // Load OCR1 to OCR4 and add them all to one image
   string[] pageFileName =
   {
      @"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Ocr1.tif",
      @"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Ocr2.tif",
      @"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Ocr3.tif",
      @"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Ocr4.tif"
   };

   // load all the files in pageFileName as pages into one image
   RasterImage image = null;

   for(int i = 0; i < pageFileName.Length; i++)
   {
      // load the page image
      RasterImage page = codecs.Load(pageFileName[i]);
      if(i == 0)
      {
         // first image, just save it into our variable
         image = page;
      }
      else
      {
         // add this page into our image
         image.AddPage(page);

         // we do not need this page anymore
         page.Dispose();
      }
   }

   // we can now use this image in our viewer.  But let us try saving into a multi-page file then reloading it

   string outputFileName = @"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Ocr_All.tif";

   // we can now just put "image" into the viewer, but lets save it as multi-page tiff and reload it
   codecs.Save(image, outputFileName, RasterImageFormat.Tif, 1, 1, 4, 1, CodecsSavePageMode.Overwrite);
   image.Dispose();

   // load this file into a new image and put in the viewer.

   // we know we have four pages, but let us use the GetInformation pages to get the number of pages
   CodecsImageInfo info = codecs.GetInformation(outputFileName, true);
   image = codecs.Load(outputFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, info.TotalPages);

   // setup the viewer into Fit mode
   rasterImageViewer1.SizeMode = RasterPaintSizeMode.Fit;

   // view this image
   rasterImageViewer1.Image = image;
   UpdateCaption();

   RasterCodecs.Shutdown();
}
   
private void UpdateCaption()
{
   Text = string.Format("Page {0} of {1}", rasterImageViewer1.Image.Page, rasterImageViewer1.Image.PageCount);
}

double-click Button1 (First) on the form to add a handler for the Click event and add the following code:

[Visual Basic]


Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
   ' goto first page
   If (RasterImageViewer1.Image.Page <> 1) Then
      RasterImageViewer1.Image.Page = 1
      UpdateCaption()
   End If
End Sub

[C#]


private void button1_Click(object sender, System.EventArgs e)
{
   // goto first page
   if(rasterImageViewer1.Image.Page != 1)
   {
      rasterImageViewer1.Image.Page = 1;
      UpdateCaption();
   }
}

double-click Button2 (Previous) on the form to add a handler for the Click event and add the following code:

[Visual Basic]


Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
   ' goto previous page
   If (RasterImageViewer1.Image.Page > 1) Then
      RasterImageViewer1.Image.Page = RasterImageViewer1.Image.Page - 1
      UpdateCaption()
   End If
End Sub

[C#]


private void button2_Click(object sender, System.EventArgs e)
{
   // goto previous page
   if(rasterImageViewer1.Image.Page > 1)
   {
      rasterImageViewer1.Image.Page--;
      UpdateCaption();
   }
}

double-click Button3 (Next) on the form to add a handler for the Click event and add the following code:

[Visual Basic]


Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
   ' goto next page
   If (RasterImageViewer1.Image.Page < RasterImageViewer1.Image.PageCount) Then
      RasterImageViewer1.Image.Page = RasterImageViewer1.Image.Page + 1
      UpdateCaption()
   End If
End Sub

[C#]


private void button3_Click(object sender, System.EventArgs e)
{
   // goto next page
   if(rasterImageViewer1.Image.Page < rasterImageViewer1.Image.PageCount)
   {
      rasterImageViewer1.Image.Page++;
      UpdateCaption();
   }
}

double-click Button4 (Last) on the form to add a handler for the Click event and add the following code:

[Visual Basic]


Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
   ' goto last page
   If (RasterImageViewer1.Image.Page <> RasterImageViewer1.Image.PageCount) Then
      RasterImageViewer1.Image.Page = RasterImageViewer1.Image.PageCount
      UpdateCaption()
   End If
End Sub

[C#]


private void button4_Click(object sender, System.EventArgs e)
{
   // goto last page
   if(rasterImageViewer1.Image.Page != rasterImageViewer1.Image.PageCount)
   {
      rasterImageViewer1.Image.Page = rasterImageViewer1.Image.PageCount;
      UpdateCaption();
   }
}

Build, and Run the program to test it.

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Writing and Reading Pages

Name	Text
Button1	First
Button2	Previous
Button3	Next
Button4	Last