SetCompressionForBitonalImage Method (GdPicturePDF)

In This Topic

Sets the scheme to be used to compress bitonal image data within the currently loaded PDF document.

Please note that firstly you need to create or load the PDF document to allow this setting to work properly. Secondly, you need to set the compression scheme before adding the required image to the current document.

Syntax

Visual Basic
C#
Delphi
JScript
Managed Extensions for C++
C++/CLI

'Declaration
 
Public Sub SetCompressionForBitonalImage( _
   ByVal Compression As PdfCompression _
)

public void SetCompressionForBitonalImage( 
   PdfCompression Compression
)

public procedure SetCompressionForBitonalImage( 
    Compression: PdfCompression
);

public function SetCompressionForBitonalImage( 
   Compression : PdfCompression
);

public: void SetCompressionForBitonalImage( 
   PdfCompression Compression
)

public:
void SetCompressionForBitonalImage( 
   PdfCompression Compression
)

Parameters

Compression: A member of the PdfCompression enumeration. The new compression scheme to be used.

Remarks

It is recommend to use the GdPicturePDF.GetStat method to identify the specific reason for the method's failure, if any. Please ensure that you have successfully created or loaded a PDF document, otherwise the method does nothing.

Example

How to set the image compression correctly.

VB.NET
C#

Dim caption As String = "Example: SetCompressionForBitonalImage"
Dim oImage As GdPictureImaging = New GdPictureImaging()
Dim imageID As Integer = oImage.CreateGdPictureImageFromFile("input.tif")
If oImage.GetStat() = GdPictureStatus.OK Then
    Dim count As Integer = oImage.GetPageCount(imageID)
    If oImage.GetStat() = GdPictureStatus.OK Then
        Dim gdpicturePDF As GdPicturePDF = New GdPicturePDF()
        'Firstly, create or load the PDF document.
        If gdpicturePDF.NewPDF() = GdPictureStatus.OK Then
            'Secondly, set the required compression.
            gdpicturePDF.SetCompressionForBitonalImage(PdfCompression.PdfCompressionCCITT4)
            Dim status As GdPictureStatus = gdpicturePDF.GetStat()
            If status = GdPictureStatus.OK Then
                'Process your document.
                For i As Integer = 1 To count
                    status = oImage.SelectPage(imageID, i)
                    If status = GdPictureStatus.OK Then
                        status = gdpicturePDF.AddImageFromGdPictureImage(imageID, PdfAdvancedImageCompression.PdfAdvancedImageCompressionNone)
                        If status <> GdPictureStatus.OK Then
                            MessageBox.Show("The AddImageFromGdPictureImage() method has failed with the status: " + status.ToString(), caption)
                            Exit For
                        End If
                    Else
                        MessageBox.Show("The SelectPage() method has failed with the status: " + status.ToString(), caption)
                        Exit For
                    End If
                Next
                'Check, if all is done without errors.
                If status = GdPictureStatus.OK Then
                    'At the end, save the file with the previously selected compression.
                    If gdpicturePDF.SaveToFile("output.pdf", False) = GdPictureStatus.OK Then
                        MessageBox.Show("Done!", caption)
                    Else
                        MessageBox.Show("The file can't be saved. Status: " + gdpicturePDF.GetStat().ToString(), caption)
                    End If
                End If
            Else
                MessageBox.Show("The SetCompressionForBitonalImage() method has failed with the status: " + status.ToString(), caption)
            End If
        Else
            MessageBox.Show("The new PDF document can't be created. Status: " + gdpicturePDF.GetStat().ToString(), caption)
        End If
    Else
        MessageBox.Show("The GetPageCount() method has failed with the status: " + oImage.GetStat().ToString(), caption)
    End If
Else
    MessageBox.Show("The image can't be created. Status: " + oImage.GetStat().ToString(), caption)
End If

string caption = "Example: SetCompressionForBitonalImage";
GdPictureImaging oImage = new GdPictureImaging();
int imageID = oImage.CreateGdPictureImageFromFile("input.tif");
if (oImage.GetStat() == GdPictureStatus.OK)
{
    int count = oImage.GetPageCount(imageID);
    if (oImage.GetStat() == GdPictureStatus.OK)
    {
        GdPicturePDF gdpicturePDF = new GdPicturePDF();
        //Firstly, create or load the PDF document.
        if (gdpicturePDF.NewPDF() == GdPictureStatus.OK)
        {
            //Secondly, set the required compression.
            gdpicturePDF.SetCompressionForBitonalImage(PdfCompression.PdfCompressionCCITT4);
            GdPictureStatus status = gdpicturePDF.GetStat();
            if (status == GdPictureStatus.OK)
            {
                //Process your document.
                for (int i = 1; i <= count; i++)
                {
                    status = oImage.SelectPage(imageID, i);
                    if (status == GdPictureStatus.OK)
                    {
                        status = gdpicturePDF.AddImageFromGdPictureImage(imageID, PdfAdvancedImageCompression.PdfAdvancedImageCompressionNone);
                        if (status != GdPictureStatus.OK)
                        {
                            MessageBox.Show("The AddImageFromGdPictureImage() method has failed with the status: " + status.ToString(), caption);
                            break;
                        }
                    }
                    else
                    {
                        MessageBox.Show("The SelectPage() method has failed with the status: " + status.ToString(), caption);
                        break;
                    }
                }
                //Check, if all is done without errors.
                if (status == GdPictureStatus.OK)
                {
                    //At the end, save the file with the previously selected compression.
                    if (gdpicturePDF.SaveToFile("output.pdf", false) == GdPictureStatus.OK)
                        MessageBox.Show("Done!", caption);
                    else
                        MessageBox.Show("The file can't be saved. Status: " + gdpicturePDF.GetStat().ToString(), caption);
                }
            }
            else
                MessageBox.Show("The SetCompressionForBitonalImage() method has failed with the status: " + status.ToString(), caption);
        }
        else
            MessageBox.Show("The new PDF document can't be created. Status: " + gdpicturePDF.GetStat().ToString(), caption);
    }
    else
        MessageBox.Show("The GetPageCount() method has failed with the status: " + oImage.GetStat().ToString(), caption);
}
else
    MessageBox.Show("The image can't be created. Status: " + oImage.GetStat().ToString(), caption);

Reference

GdPicturePDF Class
GdPicturePDF Members
SetCompressionForColorImage Method
SetJpegQuality Method