EmptyPageMode Property

C#
Visual Basic
Objective-C
Java
C++

public DocumentConverterEmptyPageMode EmptyPageMode {get; set;}

'Declaration

Public Property EmptyPageMode As DocumentConverterEmptyPageMode

'Usage

Dim instance As DocumentConverterOptions
Dim value As DocumentConverterEmptyPageMode
 
instance.EmptyPageMode = value
 
value = instance.EmptyPageMode

public DocumentConverterEmptyPageMode getEmptyPageMode()
public void setEmptyPageMode(DocumentConverterEmptyPageMode value)

public:
property DocumentConverterEmptyPageMode EmptyPageMode {
   DocumentConverterEmptyPageMode get();
   void set (    DocumentConverterEmptyPageMode value);
}

Property Value

Determines how empty pages are treated during the conversion. Default value is DocumentConverterEmptyPageMode.None.

This option controls how the document converter treats empty pages during the conversion as follows:

Value	Description
DocumentConverterEmptyPageMode.None	Do not do anything special. No detection is performed and empty pages will be added to the output document and the result is guaranteed to have the same number of pages as the input. This is the default behavior.
DocumentConverterEmptyPageMode.Skip	Empty pages are skipped and not added to the final document. If the user instructs the converter to use the annotations during conversion, then any page that is empty but has an annotation container with objects is considered none-empty and is added to the output document.
DocumentConverterEmptyPageMode.SkipIgnoreAnnotations	Similar to Empty with the annotations ignored. Empty pages are skipped even if they have annotations.

The document converter uses the following to detect if a page is empty:

If raster conversion is used, a BlankPageDetectorCommand image processing command with the options from DocumentConverterPreprocessor.BlankPageDetectorCommandFlags is run on the raster image to detect if the page is empty. The user can select other options that the default of BlankPageDetectorCommandFlags.None which only detects if the page is fully empty, for example, using margins and ignoring noise or bleed through.
If SVG conversion is used, the converter will enumerate all the elements in the page's SVG document object. The page is considered empty if it does not contain any elements besides the root <svg> element.

This example creates a test document of four pages with the second page empty (all white). It will then use the document converter to generate an output document with and without skipping empty pages.

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.Forms.DocumentWriters
Imports Leadtools.Svg
Imports Leadtools.Documents
Imports Leadtools.Caching
Imports Leadtools.Annotations.Core
Imports Leadtools.Forms.Ocr
Imports Leadtools.Documents.Converters

Public Shared Sub Run()
   Dim inputDocumentFile As String = "C:\Users\Public\Documents\LEADTOOLS Images\EmptyPageTestInput.tif"
   Dim outputDocumentFile1 As String = "C:\Users\Public\Documents\LEADTOOLS Images\NoSkipping.tif"
   Dim outputDocumentFile2 As String = "C:\Users\Public\Documents\LEADTOOLS Images\SkippingEmptyPages.tif"
   ' Create a multi-page TIF file that is 4 pages with the second page empty
   CreateTestDocumentFile(inputDocumentFile)

   Using documentConverter As New DocumentConverter()
      documentConverter.Diagnostics.EnableTrace = True

      ' Make sure the options are set to not skip empty pages
      documentConverter.Options.EmptyPageMode = DocumentConverterEmptyPageMode.None

      ' Create a job to convert the input document to the first output file and run it
      Dim jobData As DocumentConverterJobData = DocumentConverterJobs.CreateJobData(inputDocumentFile, outputDocumentFile1, RasterImageFormat.CcittGroup4)
      jobData.JobName = "No skipping empty pages"
      Dim job As DocumentConverterJob = documentConverter.Jobs.CreateJob(jobData)
      documentConverter.Jobs.RunJob(job)

      ' Now, tell the document converter to skip empty pagess
      documentConverter.Options.EmptyPageMode = DocumentConverterEmptyPageMode.SkipIgnoreAnnotations
      ' And create a job to convert the input document to the second output file and run it
      jobData = DocumentConverterJobs.CreateJobData(inputDocumentFile, outputDocumentFile2, RasterImageFormat.CcittGroup4)
      jobData.JobName = "Skipping empty pages"
      job = documentConverter.Jobs.CreateJob(jobData)
      documentConverter.Jobs.RunJob(job)

      Console.WriteLine("Finished, checking the number of pages")

      ' Show the number of pages in the first and second document, should report 4 and 3
      Using rasterCodecs As New RasterCodecs()
         rasterCodecs.Options.RasterizeDocument.Load.Resolution = 300
         Dim pageCount As Integer = rasterCodecs.GetTotalPages(outputDocumentFile1)
         Console.WriteLine("First job did not skip any pages and produced {0} pages, should be 4", pageCount)
         pageCount = rasterCodecs.GetTotalPages(outputDocumentFile2)
         Console.WriteLine("Second job skipped the empty pages and produced {0} pages, should be 3", pageCount)
      End Using
   End Using
End Sub

Private Shared Sub CreateTestDocumentFile(fileName As String)
   Dim pageTemplateFile As String = "C:\Users\Public\Documents\LEADTOOLS Images\Ocr{0}.tif"

   Using rasterCodecs As New RasterCodecs()
      rasterCodecs.Options.RasterizeDocument.Load.Resolution = 300

      Dim savePageMode As CodecsSavePageMode = CodecsSavePageMode.Overwrite

      For pageNumber As Integer = 1 To 4
         If pageNumber <> 2 Then
            Using rasterImage As RasterImage = rasterCodecs.Load(String.Format(pageTemplateFile, pageNumber), 1)
               ' Add it to the output document
               rasterCodecs.Save(rasterImage, fileName, RasterImageFormat.CcittGroup4, 1, 1, 1, -1, savePageMode)
               savePageMode = CodecsSavePageMode.Append

               If pageNumber = 1 Then
                  ' Save an empty page (all white) the same size as the previous page
                  Using emptyPage As RasterImage = rasterImage.Create( _
                     rasterImage.Width, _
                     rasterImage.Height, _
                     rasterImage.BitsPerPixel, _
                     rasterImage.XResolution, _
                     RasterColor.FromKnownColor(RasterKnownColor.White))
                     rasterCodecs.Save(emptyPage, fileName, RasterImageFormat.CcittGroup4, 1, 1, 1, -1, savePageMode)
                  End Using
               End If
            End Using
         End If
      Next
   End Using
End Sub

using Leadtools;
using Leadtools.Codecs;
using Leadtools.Forms.DocumentWriters;
using Leadtools.Svg;
using Leadtools.Documents;
using Leadtools.Caching;
using Leadtools.Annotations.Core;
using Leadtools.Forms.Ocr;
using Leadtools.Documents.Converters;

public static void Run()
{
   var inputDocumentFile = @"C:\Users\Public\Documents\LEADTOOLS Images\EmptyPageTestInput.tif";
   var outputDocumentFile1 = @"C:\Users\Public\Documents\LEADTOOLS Images\NoSkipping.tif";
   var outputDocumentFile2 = @"C:\Users\Public\Documents\LEADTOOLS Images\SkippingEmptyPages.tif";
   // Create a multi-page TIF file that is 4 pages with the second page empty
   CreateTestDocumentFile(inputDocumentFile);

   using (DocumentConverter documentConverter = new DocumentConverter())
   {
      documentConverter.Diagnostics.EnableTrace = true;

      // Make sure the options are set to not skip empty pages
      documentConverter.Options.EmptyPageMode = DocumentConverterEmptyPageMode.None;

      // Create a job to convert the input document to the first output file and run it
      var jobData = DocumentConverterJobs.CreateJobData(inputDocumentFile, outputDocumentFile1, RasterImageFormat.CcittGroup4);
      jobData.JobName = "No skipping empty pages";
      var job = documentConverter.Jobs.CreateJob(jobData);
      documentConverter.Jobs.RunJob(job);

      // Now, tell the document converter to skip empty pagess
      documentConverter.Options.EmptyPageMode = DocumentConverterEmptyPageMode.SkipIgnoreAnnotations;
      // And create a job to convert the input document to the second output file and run it
      jobData = DocumentConverterJobs.CreateJobData(inputDocumentFile, outputDocumentFile2, RasterImageFormat.CcittGroup4);
      jobData.JobName = "Skipping empty pages";
      job = documentConverter.Jobs.CreateJob(jobData);
      documentConverter.Jobs.RunJob(job);

      Console.WriteLine("Finished, checking the number of pages");

      // Show the number of pages in the first and second document, should report 4 and 3
      using (var rasterCodecs = new RasterCodecs())
      {
         var pageCount = rasterCodecs.GetTotalPages(outputDocumentFile1);
         Console.WriteLine("First job did not skip any pages and produced {0} pages, should be 4", pageCount);
         pageCount = rasterCodecs.GetTotalPages(outputDocumentFile2);
         Console.WriteLine("Second job skipped the empty pages and produced {0} pages, should be 3", pageCount);
      }
   }
}

private static void CreateTestDocumentFile(string fileName)
{
   var pageTemplateFile = @"C:\Users\Public\Documents\LEADTOOLS Images\Ocr{0}.tif";

   using (var rasterCodecs = new RasterCodecs())
   {
      rasterCodecs.Options.RasterizeDocument.Load.Resolution = 300;

      CodecsSavePageMode savePageMode = CodecsSavePageMode.Overwrite;

      for (var pageNumber = 1; pageNumber <= 4; pageNumber++)
      {
         if (pageNumber != 2)
         {
            using (var rasterImage = rasterCodecs.Load(string.Format(pageTemplateFile, pageNumber), 1))
            {
               // Add it to the output document
               rasterCodecs.Save(rasterImage, fileName, RasterImageFormat.CcittGroup4, 1, 1, 1, -1, savePageMode);
               savePageMode = CodecsSavePageMode.Append;

               if (pageNumber == 1)
               {
                  // Save an empty page (all white) the same size as the previous page
                  using (var emptyPage = RasterImage.Create(
                     rasterImage.Width,
                     rasterImage.Height,
                     rasterImage.BitsPerPixel,
                     rasterImage.XResolution,
                     RasterColor.FromKnownColor(RasterKnownColor.White)))
                  {
                     rasterCodecs.Save(emptyPage, fileName, RasterImageFormat.CcittGroup4, 1, 1, 1, -1, savePageMode);
                  }
               }
            }
         }
      }
   }
}

Target Platforms

Reference

DocumentConverterOptions Class
DocumentConverterOptions Members